When a potential customer asks ChatGPT “who is the best plumber in Sacramento?” or types “top dentists near me” into Google, which businesses show up? More importantly—is yours one of them?
Until now, there was no standardized way to measure how visible a local business truly is across both traditional search and AI-powered discovery platforms. Search rankings tell part of the story. Google reviews tell another part. But neither captures the full picture of whether AI systems like ChatGPT, Perplexity, Google AI Overviews, and Claude can find, understand, and recommend your business.
That's why we built the Sigma Visibility Index™.
What Is the Sigma Visibility Index™?
The Sigma Visibility Index™ is a public ranking system that measures how discoverable local businesses are across Google Search, Google Maps, AI search engines, and answer engines. Every business receives a Sigma Score—a 100-point rating calculated across three weighted categories—and is ranked against competitors in their industry and city.
Think of it as the definitive visibility benchmark for local businesses. Not just how well you rank on Google, but how well AI systems can find you, understand what you do, and recommend you to potential customers.
See where your business ranks. Run a free Sigma Score scan →
How the Sigma Score Is Calculated
Every business in the Sigma Visibility Index™ is scored on a 100-point scale across three categories:
SEO — 40% of Score
Traditional search engine optimization signals: meta titles and descriptions, heading structure, image optimization, internal linking, mobile responsiveness, page speed, canonical URLs, sitemap presence, and robots.txt configuration. This is the foundation—if search engines can't crawl and understand your site, nothing else matters.
Local SEO — 30% of Score
Local search visibility signals: LocalBusiness schema markup, NAP (Name, Address, Phone) consistency, Google Business Profile optimization, service area coverage, local citation signals, and review schema. These determine whether you show up when someone searches for your service in your city.
AEO (Answer Engine Optimization) — 30% of Score
AI search readiness signals: structured data and schema markup depth, FAQ schema implementation, AI crawler accessibility, llms.txt file presence, content structured for direct-answer extraction, and semantic markup clarity. This category determines whether ChatGPT, Perplexity, and Google AI Overviews can find and cite your business.
Why Traditional SEO Is No Longer Enough
In 2026, search behavior has fundamentally shifted. Zero-click searches—where users get answers directly from AI without visiting a website—now dominate consumer behavior. When someone asks Google a question, they increasingly see an AI Overview rather than a list of blue links. When they ask ChatGPT or Perplexity for a recommendation, the AI synthesizes information from structured sources and delivers a direct answer.
This means the new competitive battleground isn't just ranking on page one of Google. It's being cited inside AI-generated answers. A business that scores 90 on traditional SEO but 20 on AEO is invisible to the fastest-growing search channel. The Sigma Visibility Index™ captures this reality by weighting AI readiness as heavily as local search signals.
How the Rankings Work
The Sigma Visibility Index™ ranks businesses within their industry and city. When you visit a leaderboard page—for example, Top Plumbers in Sacramento, CA—you see every scanned business ranked from highest to lowest Sigma Score.
Each listing shows the business name, overall Sigma Score, letter grade (A+ through F), individual category scores, and the top issues holding them back. Businesses can click through to a full detailed report showing every check that passed, warned, or failed.
Rankings are updated weekly through automated re-scans, and new businesses are added when they run a free scan or are discovered through on-demand leaderboard scans.
What Small Businesses Can Learn from Their Ranking
The Sigma Visibility Index™ isn't just a ranking—it's a diagnostic tool. Here's what your position reveals:
- Grade A+ or A (80-100): Your business is highly visible across both traditional and AI search. You're likely being cited by ChatGPT and appearing in Google AI Overviews. Focus on maintaining your position and monitoring competitors.
- Grade B+ or B (60-79): You have a solid foundation but significant gaps. You're probably ranking on Google but missing from AI-generated recommendations. Common fixes: adding FAQ schema, enabling AI crawlers, implementing structured data.
- Grade C (50-59): Below average. Your competitors are likely outranking you in both Google and AI search. This is the danger zone—you're losing leads to businesses with better visibility infrastructure.
- Grade D or F (below 50): Largely invisible to AI search. When customers ask ChatGPT or Perplexity for recommendations in your industry and city, your business does not appear. Every day at this level means lost customers going to AI-visible competitors.
The Visibility Gap: Your Biggest Opportunity
One of the most powerful features of the Sigma Visibility Index™ is the visibility gap analysis. On every leaderboard page, you can see the gap between the top-performing business and the average score. In most markets, this gap is enormous—often 40 or more points.
This gap represents a massive opportunity. If the top plumber in your city scores 85 and the average is 42, the first business to invest in closing that gap captures an outsized share of AI-driven leads. Early movers in AI visibility are building a compounding advantage that becomes harder to overcome as AI search adoption accelerates.
Find the visibility gap in your market. Browse the Sigma Visibility Index™ →
How to Improve Your Ranking
Every Sigma Score scan identifies specific issues holding your score down. The most common fixes that produce the biggest score improvements:
- 1.Add structured data and schema markup. LocalBusiness, Service, FAQ, and Organization schema help both Google and AI systems understand what your business does. This is the single highest-impact change for most businesses.
- 2.Implement FAQ schema. AI systems are specifically designed to extract question-and-answer content. Adding FAQ schema to your key service pages makes your business citable by ChatGPT, Perplexity, and Google AI Overviews.
- 3.Allow AI crawlers in your robots.txt. Many websites inadvertently block AI crawlers like GPTBot and ClaudeBot. Ensuring these crawlers have access is essential for AI discoverability.
- 4.Add an llms.txt file. This emerging standard provides AI systems with a structured map of your most important content, reducing parsing complexity and improving citation accuracy.
- 5.Fix NAP consistency. Your business Name, Address, and Phone number must be consistent across your website, Google Business Profile, and all online directories. Inconsistency confuses both search engines and AI systems.
Coverage: 89 Industries, Thousands of Cities
The Sigma Visibility Index™ covers 89 industries across the United States, United Kingdom, Canada, and Australia. From plumbers and dentists to lawyers and real estate agents, every local service industry has dedicated leaderboard pages for major cities in each region.
This creates one of the first public benchmarks for AI visibility adoption among local businesses—a national dataset showing which industries and markets are leading in AI readiness and which are falling behind.
The Bottom Line
The businesses that invest in AI visibility now are building a compounding advantage. As AI search adoption grows, the gap between AI-visible businesses and invisible ones will widen. The Sigma Visibility Index™ gives every local business a clear picture of where they stand and exactly what to do about it.
Your competitors are already being ranked. The question is whether you're going to see your score—and do something about it.