What is RankEmbed?
RankEmbed is a deep learning model Google uses to rank and retrieve web content for search results. The system converts both search queries and web pages into numerical representations called vectors. These vectors capture the meaning behind text rather than just matching keywords.
Think of it like this: Traditional search is like looking for exact words in a phone book. RankEmbed is like having a conversation where someone understands what you mean, even if you use different words.
Google revealed RankEmbed through court documents in its 2025 antitrust case. The model powers Google’s AI Overviews and a specialized technology called FastSearch.
Key Takeaways:
- RankEmbed is Google’s semantic search model that understands meaning, not just keywords
- The system powers AI Overviews, which appear at the top of search results
- Home service businesses need to optimize for both traditional SEO and semantic relevance
- Informational content sees the biggest impact from AI Overviews (10-60% traffic changes)
- Service queries (“plumber near me”) still rely heavily on Google Business Profile
- Start optimizing now with your highest-traffic pages to maintain competitive visibility
- Professional help costs $500-$5,000 initially, plus $1,000-$5,000 monthly for ongoing work
- Traditional SEO fundamentals (backlinks, page speed, local optimization) still matter
- Content should answer questions directly in the first 100 words with clear structure
- Results typically appear within 3-6 months of implementing semantic optimization
How RankEmbed Works
RankEmbed operates differently from traditional search ranking. Instead of counting keywords or analyzing backlinks, the model understands semantic relationships.
The system takes a search query and converts it into a vector. A vector is a series of numbers representing meaning. RankEmbed does the same thing with web page content. The model then compares these vectors to find content matching what the user wants to know.
Here’s a real example for home service businesses: If someone searches for “emergency water heater repair near me,” RankEmbed recognizes pages about “24-hour plumbing services” or “same-day water heater replacement” are semantically related. The exact words do not need to match.
Training Data
RankEmbed learns from three main sources:
- 70 days of search logs showing real user behavior
- Quality scores from human raters who evaluate content
- Click and query data revealing which results users find helpful
The model uses 1/100th of the data earlier ranking models required. Despite using less data, RankEmbed delivers higher quality results for long-tail queries.
Why RankEmbed Matters for Your Business
RankEmbed changes how Google evaluates your website content. Your business needs to understand this shift because the old rules are changing right now.
Traditional SEO focused on keywords and backlinks. RankEmbed focuses on meaning and relevance. A page with fewer backlinks but clear topical relevance now outranks a high-authority domain with vague content.
This shift is happening today, not years from now. Businesses adapting to RankEmbed principles are gaining competitive advantages while others lose visibility.
Impact on Website Visibility
Google’s AI Overviews use RankEmbed signals through FastSearch technology. When someone searches for information, AI Overviews appear at the top of results. These overviews pull information from web pages RankEmbed identifies as semantically relevant.
If your content does not match RankEmbed’s semantic criteria, you lose visibility. Users get their answers from AI Overviews without visiting your website. This means less traffic for businesses relying on informational content.
Research shows AI Overviews reduce click-through rates by 15 to 25 percent for traditional search results. Informational content fully addressed by AI Overviews sees traffic drops of 40 to 60 percent. Service-based queries for home service businesses typically see smaller impacts of 10 to 20 percent because local results and Google Business Profile still dominate these searches.
What This Means for Home Service Businesses
Home service businesses face specific challenges and opportunities with RankEmbed. The impact varies by query type.
Service Queries like “plumber near me,” “emergency HVAC repair,” or “roofing contractor Dallas” still rely heavily on Google Business Profile and the local map pack. RankEmbed has minimal impact here right now. Your Google Business Profile optimization remains your top priority for these searches.
Informational Queries like “how to fix a leaky faucet,” “signs you need a new roof,” or “when to replace your water heater” are heavily impacted by AI Overviews. These queries now get direct answers at the top of search results.
Comparison Queries like “tankless vs tank water heater” or “central AC vs ductless mini split” see moderate AI Overview impact. Google often shows comparison information in AI Overviews while still displaying traditional results.
Understanding the Customer Journey
RankEmbed affects different stages of your customer journey differently:
Awareness Stage: Potential customers research problems and solutions. They search “why is my furnace making noise” or “how long do roofs last.” AI Overviews answer these questions directly. Your goal: Get cited as a source to build brand awareness.
Consideration Stage: Customers compare options and providers. They search “best HVAC brands” or “roof replacement cost.” AI Overviews provide overviews, but customers still click through for details. Your goal: Create comprehensive guides that get cited and earn clicks.
Decision Stage: Customers ready to hire search “plumber near me” or “roofing contractor reviews.” Google Business Profile and local pack dominate these results. Your goal: Maintain strong local SEO with reviews, accurate information, and local citations.
RankEmbed primarily affects awareness and consideration stages. Your local SEO work for decision-stage queries remains critical.
Real Scenarios:
When potential customers search “how to fix a leaky faucet,” AI Overviews answer their questions directly. Your plumbing business loses the chance to capture the visitor and offer professional service. But if Google cites your content, you gain brand recognition.
When someone searches “signs you need a new roof,” AI Overviews provide the answer. Your roofing company misses the opportunity to educate and convert the homeowner immediately. But being cited builds authority that leads to branded searches later.
When a homeowner searches “how long does HVAC installation take,” AI Overviews give the timeframe. Your HVAC business loses a chance to explain your process. But citation establishes you as the local expert.
The Opportunity:
Being cited as a source in AI Overviews builds authority. When Google’s AI references your content, potential customers see your business name. Users who do click through are better informed and more likely to convert.
A cited HVAC company gets brand recognition even if users do not click immediately. When they need service later, they remember the name Google trusted. This brand awareness drives direct searches and phone calls.
How to Optimize for RankEmbed
Your content strategy needs to adapt to semantic search principles. Start making these changes now to stay competitive.
Write for humans first. Use natural language matching how people speak and search. Stop stuffing keywords into awkward sentences.
Example: Instead of “HVAC repair services Dallas Texas emergency,” write “We provide emergency HVAC repair in Dallas when your system breaks down.”
Answer questions directly. Put your main point in the first 100 words. Users and AI systems both need to understand your topic immediately.
Example: Start your blog post with “A new roof typically lasts 20 to 25 years with asphalt shingles” instead of three paragraphs of background first.
Cover topics comprehensively. Create content exploring a subject from multiple angles. Link related pages together to show semantic relationships.
Example: A comprehensive guide to water heater problems should cover warning signs, common causes, repair versus replacement, costs, and maintenance tips.
Structure content for easy extraction. Use clear headings asking and answering questions. Break information into short paragraphs and bullet lists. Make key points stand out.
Example: Use headings like “What causes AC units to freeze?” and “How much does furnace repair cost?” instead of vague headings like “Common issues” or “Pricing information.”
Implement schema markup. This code helps search engines understand your content structure. Use Article, FAQPage, and HowTo schema types.
Your web developer or SEO specialist handles the technical implementation. Basic schema markup costs $500 to $2,000 for small business websites. Ongoing schema maintenance adds $100 to $300 monthly. The investment pays off through improved visibility.
Content Example: Before and After Optimization
Before (Keyword-Focused):
Heading: “AC Services”
Content: “Our company provides AC services in Dallas. We do AC repair, AC installation, and AC maintenance. Call us for AC services. We are the best AC company in Dallas with experienced AC technicians.”
Problems: Repetitive keywords, no clear answer, vague information, poor user experience.
After (Semantic-Focused):
Heading: “What Air Conditioning Services Do We Provide in Dallas?”
Content: “We offer three main AC services for Dallas homeowners. AC repair addresses immediate problems like refrigerant leaks or compressor failure, typically completed within 24 hours. AC installation replaces your entire system, taking 4 to 8 hours for most homes. AC maintenance includes seasonal tune-ups to prevent breakdowns and extend system life. Schedule service online or call 214-555-0100 for same-day emergency repairs.”
Improvements: Clear question-based heading, direct answer, specific details, natural language, better user experience.
This restructured content performs better for both traditional search and RankEmbed because it genuinely helps users while maintaining semantic clarity.
The Semantic Search Shift
Semantic search means understanding intent and meaning rather than matching text strings. RankEmbed excels at this approach.
Your old keyword strategy targeted specific phrases like “plumber in Austin” or “roof repair Dallas.” Your new strategy should target concepts and user intent like “emergency plumbing solutions” or “roof damage assessment.”
Think about what customers want to know. Create content genuinely helping them. Make your expertise obvious through comprehensive coverage and clear explanations.
RankEmbed vs Traditional Ranking
Traditional Google Search uses hundreds of ranking signals. These include backlinks, domain authority, page speed, mobile optimization, and content quality.
RankEmbed prioritizes semantic relevance. The model asks: How closely does this content align with what the user means?
Both systems still matter. Traditional search drives most traffic today. RankEmbed powers the growing AI Overview feature. You need to optimize for both, not choose one over the other.
Keep building quality backlinks from local business directories, industry associations, and local news sites. Maintain fast page speeds and mobile optimization. Ensure your Google Business Profile stays updated. Add semantic optimization on top of these fundamentals.
FastSearch Technology
Google uses RankEmbed signals in a specialized system called FastSearch. This technology powers AI Overviews by retrieving relevant content quickly.
FastSearch makes three compromises for speed:
- It searches a smaller pool of documents instead of Google’s full index.
- It uses simplified ranking signals focused on semantic relevance rather than comprehensive analysis.
- It accepts lower quality thresholds compared to traditional search results.
Google acknowledged in court documents FastSearch results are “lower quality than Search’s fully ranked web results” but “good enough for grounding” AI responses.
This explains why AI Overviews sometimes cite unexpected sources. FastSearch prioritizes semantic matching and speed over comprehensive quality analysis.
Content Performing Well
Certain content structures work better for RankEmbed and AI Overviews.
Direct question and answer formats get cited frequently. Start with the question as a heading. Provide a complete answer in 150 to 250 words.
Example: “How long does AC installation take? Most residential AC installations take 4 to 8 hours. The process includes removing the old unit, installing the new system, connecting refrigerant lines, testing operation, and reviewing controls with the homeowner. Complex installations with ductwork modifications take 1 to 2 days.”
Step by step instructions with numbered lists perform well. Users and AI systems both appreciate clear sequences.
Example: “How to prepare for a roof inspection: 1. Clear debris from gutters and downspouts. 2. Trim overhanging tree branches within 6 feet of the roof. 3. Document visible damage with dated photos. 4. List any leaks or interior water stains you’ve noticed. 5. Prepare questions about roof age, remaining lifespan, and repair priorities.”
Comparison tables showing differences between options get extracted often. Structure makes information easy to understand.
Example: Create a table comparing tankless water heaters versus traditional tank models, showing upfront costs, installation requirements, lifespan, energy efficiency, and best use cases.
Definition lists with clear explanations help establish semantic clarity.
Example: “What is SEER rating? SEER stands for Seasonal Energy Efficiency Ratio. The rating measures how efficiently an AC unit operates over a typical cooling season. Higher SEER ratings mean lower energy costs. Modern units range from 14 SEER (minimum efficiency) to 25+ SEER (high efficiency). Each 1-point SEER increase reduces cooling costs by approximately 5 to 7 percent.”
What to Avoid
Some content approaches hurt your chances with RankEmbed.
Long blocks of unbroken text make extraction difficult. Break content into scannable sections with clear headings and short paragraphs of 2 to 4 sentences.
Ambiguous or creative headings confuse semantic analysis. Use descriptive headings clearly stating the topic. “Winter woes” is creative but unclear. “Common furnace problems in winter” is clear and semantic.
Content requiring external context to understand performs poorly. Make each section self-contained. Do not write “As mentioned above” or “See our previous post.” Include necessary information in each section so it works independently.
Excessive technical jargon without explanation reduces accessibility. Explain terms clearly for your audience. Define BTU, SEER, R-value, and other industry terms when you use them. Remember your customers are homeowners, not HVAC technicians.
Overly salesy content without educational value gets ignored. AI Overviews cite helpful information, not promotional pitches. Educate first, promote second.
Measuring Success
Track your performance separately for traditional search and AI Overviews. Measurement takes consistent effort but reveals what works.
How to Check for AI Overview Appearances:
Open an incognito browser window to avoid personalized results. Search your target keywords monthly. Document when AI Overviews appear and which sources get cited. Take screenshots for your records. Note whether your business appears in citations.
Google Search Console Reports to Monitor:
Check the Performance report for total clicks and impressions monthly. Filter by page to see which content drives traffic. Compare month-over-month changes. Look for pages losing impressions (possible AI Overview impact) and pages gaining impressions (successful optimization).
Review the Pages report to identify your highest-traffic content. These pages are your optimization priorities. Small improvements here have the biggest impact.
Check the Queries report to see which searches bring traffic. Identify informational queries where you rank well but traffic is declining (likely AI Overview impact).
What Success Looks Like:
Success means maintaining or growing traffic despite AI Overview expansion. If competitors lose 30 percent traffic to AI Overviews but you lose only 10 percent, you are winning.
Success means appearing as a cited source in AI Overviews for your target topics. Citations build brand awareness even without immediate clicks.
Success means higher conversion rates from organic traffic. Users clicking through after reading AI Overviews are better informed and more qualified.
Warning Signs to Address:
Traffic declines of 30 percent or more on informational content within 3 to 6 months indicate AI Overview impact without successful citations. Restructure this content with better semantic optimization.
Competitors appearing in AI Overviews while you do not indicates they have stronger semantic signals. Analyze their content structure and topic coverage.
Declining rankings for service queries (“plumber near me”) indicate traditional local SEO problems, not RankEmbed issues. Focus on Google Business Profile optimization, reviews, and local citations.
Optimization Priority Framework
Business owners need to know what to do first. Use this priority framework to focus your efforts.
High Priority Quick Wins (Start Here):
Restructure your top 10 highest-traffic pages with question-based headings and direct answers. These pages already have authority and traffic. Small improvements yield immediate results.
Add FAQ schema markup to pages with common questions. This technical change takes minimal time but improves semantic clarity.
Update your Google Business Profile with complete information, fresh photos, and consistent posting. This protects your local search visibility while you work on semantic optimization.
High Priority Longer Term (Months 2-4):
Create comprehensive guides on your core services. Write the definitive resource on furnace maintenance, roof replacement, or water heater selection. Aim for 2,000 to 3,000 words with clear structure.
Build topic clusters by linking related content. Connect your AC repair page to troubleshooting guides, maintenance tips, and replacement information.
Develop content answering the questions customers ask during sales calls. Turn your team’s expertise into optimized Q&A content.
Medium Priority (Months 5-8):
Implement comprehensive schema markup across your website. Work with your developer to add Article, HowTo, and LocalBusiness schema.
Expand content into adjacent topics. HVAC companies write about indoor air quality and humidity control. Plumbers write about water quality and conservation.
Create seasonal content addressing timely concerns. Winter furnace tips, summer AC efficiency, spring plumbing maintenance, fall roof inspections.
Lower Priority (Months 9-12):
Develop advanced content like cost calculators, product selectors, or interactive tools. These require more investment but create unique value AI cannot replicate.
Build content partnerships with complementary businesses. Co-create guides with real estate agents, home inspectors, or insurance providers.
Experiment with video content and alternative formats. Diversify beyond text-based content.
When to Take Action
Start optimizing for RankEmbed now. Businesses waiting to adapt will fall behind competitors who act today.
AI Overviews are expanding to more query types throughout 2025 and 2026. Early adopters gain first-mover advantages. Your competitors are either adapting already or will start soon.
The businesses establishing semantic authority now will dominate AI Overview citations for years. RankEmbed learns from historical performance. Early success influences future selection.
Realistic Timeline for Results:
Months 1-2: Audit your content and identify high-priority pages. Note: Most businesses need professional help for comprehensive audits. DIY audits should focus on your top 10 to 20 pages, not your entire website.
Months 3-4: Restructure key pages with semantic optimization. Expect to see initial ranking improvements for some keywords. Full impact takes longer.
Months 5-6: Expand optimization across your website. Monitor results and refine your approach. Some pages will perform better than others. Learn from successes.
Months 7-12: See measurable traffic stabilization or growth. Establish authority through consistent AI Overview citations. Competitive positioning strengthens as others struggle to adapt.
The Future of Search
RankEmbed represents Google’s direction for search technology. AI-powered experiences will become more common, not less.
Understanding semantic search and optimizing for meaning rather than keywords prepares your business for this shift. The businesses thriving in 2026 and beyond will be those adapting today.
The core principle remains unchanged: create clear, helpful, authoritative content serving users. RankEmbed rewards content genuinely answering questions and demonstrating expertise.
Balancing Traditional SEO and RankEmbed
You do not need to abandon traditional SEO practices. You need to expand your strategy.
Continue building backlinks from reputable local business directories, industry associations, and local news sites. Backlinks still drive traditional rankings and establish authority.
Maintain technical excellence with fast page speeds, mobile optimization, and proper site structure. Technical SEO still matters for both traditional search and user experience.
Keep your Google Business Profile updated with accurate information, photos, customer reviews, and regular posts. Local SEO remains critical for home service businesses. This is your foundation.
Add semantic optimization on top of these fundamentals. Restructure content with clear headings. Answer questions directly. Cover topics comprehensively. Use natural language.
The winning strategy combines traditional SEO strength with semantic clarity. Do not choose one over the other.
Getting Professional Help
Most home service business owners do not have time to implement these changes themselves. You run a business. You fix roofs, repair HVAC systems, or handle plumbing emergencies.
Working with a qualified SEO specialist or digital marketing agency familiar with semantic search and RankEmbed optimization makes sense. The investment pays off through maintained or improved visibility while competitors lose ground.
What to Look For in an SEO Specialist:
Experience with semantic search optimization and AI Overviews. Ask for specific examples of clients they have helped with RankEmbed optimization.
Understanding of home service business models. Your industry has unique needs. Local SEO expertise matters more than national campaign experience.
Transparent reporting and communication. You should receive monthly reports showing traffic, rankings, and AI Overview appearances. Avoid anyone promising “guaranteed rankings” or “instant results.”
Realistic timelines and expectations. Quality SEO takes 3 to 6 months to show results. Be skeptical of promises of immediate improvements.
Clear pricing and contract terms. Understand what services are included and what costs extra. Avoid long-term contracts with early cancellation penalties.
What Professional Help Costs:
Initial website audit and strategy: $1,000 to $3,000 for small businesses. Comprehensive audits for larger businesses cost $3,000 to $10,000.
Content optimization: $150 to $300 per page for restructuring existing content. New comprehensive guide creation costs $500 to $1,500 per article.
Schema markup implementation: $500 to $2,000 for basic implementation across a small website. Complex schema for larger sites costs $2,000 to $5,000.
Ongoing optimization and monitoring: $1,000 to $5,000 monthly depending on website size, competition level, and service scope.
These investments should generate positive ROI through maintained traffic and lead generation. Compare costs to your customer lifetime value.
Red Flags to Avoid:
Promises of “first page rankings” or “guaranteed results.” No one controls Google’s algorithms.
Requests for long-term contracts (12+ months) with penalties for early cancellation. Quality work should earn continued business.
Lack of transparency about methods or unwillingness to explain strategies. You should understand what they are doing and why.
Focus only on rankings without discussing traffic, leads, or business results. Rankings mean nothing without business impact.
Extremely low prices ($200 to $500 monthly). Quality SEO requires significant time and expertise. Bargain pricing usually means outsourced, low-quality work.
Questions to Ask Potential Vendors:
How do you stay current with Google algorithm changes and new technologies like RankEmbed?
What specific experience do you have with home service businesses in my industry?
How do you measure success, and what results have you achieved for similar clients?
What is included in your monthly service, and what costs extra?
How often will we communicate, and what reporting will I receive?
What happens if I need to cancel, and what are the terms?
Who will actually do the work? Will it be you, your team, or outsourced contractors?
Competitive Intelligence
Understanding what competitors do successfully helps you improve your strategy.
Monthly Competitive Monitoring:
Search your key service terms in incognito mode. “HVAC repair [your city],” “plumber near me,” “roof replacement [your city].”
Document which competitors appear in AI Overviews. Take screenshots with dates. Track changes month-over-month.
Analyze their content structure. What headings do they use? How do they answer questions? What topics do they cover?
Identify content gaps. What questions do they answer that you do not? What topics do they cover comprehensively that you only mention briefly?
Note their schema markup using browser extensions like Schema Markup Validator. See what structured data they implement.
Learning from Competitors:
If a competitor gets cited in AI Overviews consistently, study their approach. What makes their content semantically clear? How do they structure information? What depth do they provide?
Do not copy their content. Learn from their structure and approach. Then create something better with your unique expertise and perspective.
Look for weaknesses in competitor content. Vague answers, missing information, poor structure, or outdated details create opportunities. Fill these gaps with superior content.
Content Repurposing Strategy
Home service businesses often have limited time and resources for content creation. Repurposing existing content maximizes your investment.
Turn Service Pages into Comprehensive Guides:
Your basic “AC Repair” page lists services. Expand it into “The Complete Guide to AC Repair: Common Problems, Costs, and When to Call Professionals.”
Add sections answering: What are common AC problems? How much does AC repair cost? When should you repair versus replace? How do you choose an AC repair company? What happens during a repair visit?
This expanded content serves users better and provides more semantic signals for RankEmbed.
Convert Customer FAQs into Optimized Content:
Your team answers the same questions repeatedly. “How long does installation take?” “Do you offer financing?” “What brands do you recommend?”
Create dedicated pages or blog posts answering each question comprehensively. Use the question as your H1 heading. Provide a complete answer in the first paragraph. Add supporting details, examples, and related information.
Implement FAQ schema markup to help search engines understand the Q&A structure.
Repurpose Seasonal Advice:
You send seasonal maintenance reminders to customers. “Schedule your fall furnace tune-up” or “Prepare your AC for summer.”
Turn these reminders into comprehensive seasonal guides. “Fall HVAC Maintenance Checklist: 12 Steps to Prepare Your System for Winter” or “Summer AC Efficiency Guide: How to Keep Your Home Cool and Save Money.”
These guides provide value beyond simple service reminders and create semantic-rich content.
Simple Glossary of Terms
Understanding key terms helps you communicate with SEO specialists and understand your strategy.
Semantic Search: Search technology understanding meaning and intent rather than just matching keywords. RankEmbed is Google’s semantic search model.
Vectors: Numerical representations of meaning. RankEmbed converts queries and content into vectors to compare semantic similarity.
Schema Markup: Code added to your website helping search engines understand content structure. Common types include Article, FAQPage, HowTo, and LocalBusiness schema.
AI Overviews: Google’s AI-generated answers appearing at the top of search results. Powered by Gemini AI using FastSearch technology.
FastSearch: Google’s specialized retrieval system using RankEmbed signals to quickly find content for AI Overviews. Prioritizes speed and semantic relevance over comprehensive analysis.
Long-Tail Queries: Longer, more specific search phrases. “How much does tankless water heater installation cost in Dallas” versus “water heater cost.” RankEmbed excels at understanding long-tail queries.
Local Pack: The map and three business listings appearing for local searches. Still dominated by Google Business Profile optimization, minimally impacted by RankEmbed currently.
Click-Through Rate (CTR): Percentage of people who see your search result and click through to your website. AI Overviews reduce CTR for some query types.
Topic Cluster: Group of related content pages linked together around a central topic. Helps establish semantic relationships and topical authority.
User Intent: What the searcher actually wants to accomplish. Informational (learn something), navigational (find a specific site), transactional (buy or hire), or commercial investigation (compare options).
Action Steps for Your Business
Start with a content audit. Review your existing pages to ensure they clearly address user intent from the opening paragraph. Focus on your top 10 to 20 highest-traffic pages first.
Identify ambiguity in your content. Strengthen explicit topic relationships between related pages. Link your water heater repair page to your emergency plumbing page and your preventive maintenance page.
Restructure important pages using question-based headings and scannable formats. Turn “Services” into “What plumbing services do we offer?” Turn “About our process” into “How does our roof inspection work?”
Add schema markup to help search engines understand your content structure. Work with your web developer to implement Article, FAQPage, and HowTo schema on appropriate pages. Budget $500 to $2,000 for initial implementation.
Create comprehensive guides on topics relevant to your services. Go deeper than competitors. Write the definitive guide to furnace maintenance or the complete explanation of roof warranties. Aim for 2,000 to 3,000 words with clear structure.
Monitor your results. Track which changes improve visibility in both traditional search and AI Overviews. Check Google Search Console monthly. Search your key terms in incognito mode to see AI Overview appearances. Adjust your strategy based on what works for your business.
Key Takeaway
RankEmbed changes how Google evaluates content by focusing on semantic meaning rather than keyword matching. Your business needs clear, comprehensive content directly answering user questions. Traditional SEO fundamentals still matter, but semantic optimization is now essential for maintaining visibility as AI-powered search expands. Start adapting your content strategy now to stay competitive in 2025 and beyond. Most businesses benefit from professional help costing $2,000 to $5,000 initially plus $1,000 to $5,000 monthly for ongoing optimization.