The AI Visibility Gap
Of 1,918 California plumbers tracked on VerifiedNode, the average AI Trust Score is 21.5/100. The median is 22.0/100. Those numbers mean the typical California plumber is effectively invisible to AI assistants that surface contractor recommendations to homeowners searching right now.
Every contractor in the dataset has a website. That 100% website presence rate sounds like a baseline win. The scores tell a different story.
Having a website is not the same as being readable by AI systems. Structured data is what bridges that gap, and only 11% of California plumbers (roughly 211 of 1,918) have implemented JSON-LD markup. That's above the national average of 8.6% across 74,620 businesses tracked, but it still leaves 89% of the state's plumbers without the machine-readable signals that AI assistants rely on to verify and recommend local contractors.
The score distribution makes the problem concrete:
| Score Range | Contractors | Share of State |
|---|---|---|
| 0-9 | 926 | 48.0% |
| 10-19 | 3 | 0.0% |
| 20-29 | 220 | 11.0% |
| 30-39 | 299 | 16.0% |
| 40-59 | 318 | 17.0% |
| 60-79 | 127 | 7.0% |
| 80-100 | 25 | 1.5% |
Nearly half of all California plumbers score between 0 and 9. Only 1.5% reach the Excellent tier (80-100). The bottom 50% average 1.2/100. The top 10% average 67.3/100. That 66-point gap is not a marginal difference in visibility: it's the difference between being recommended and being absent.
The review picture reinforces this divide. The bottom 50% average 19.0 reviews per business. The top 10% average 38.0 reviews, a 2x gap that directly affects Legitimacy scoring, the heaviest component in the AI Trust Score framework.
The score is built from three components: Identity (25 points, covering business name, address, and phone consistency), Legitimacy (35 points, covering reviews, ratings, and license and insurance verification), and Readability (40 points, covering website quality, JSON-LD structured data, and mobile-friendliness). Most California plumbers are losing points across all three, but Readability is where the gap is widest.
California's 21.5 state average compares poorly against Texas (35.7/100) and Ontario (38.5/100). Within California, plumbers as a vertical do outperform the state's overall contractor mix, averaging 47.7/100 with 30% JSON-LD adoption. That suggests the contractors who have invested in structured data are pulling the vertical average up. The majority have not made that investment.
If you want to know where your business sits in this distribution, check your score at /find or browse the full California plumber directory to see how your market compares.
What AI Models Check
AI assistants don't read your website the way a homeowner does. They parse structured signals, cross-reference identity data, and weigh legitimacy indicators before surfacing a recommendation. Three scoring categories determine whether you appear in those results.
Identity: 25 points. This measures whether your business name, address, and phone number are consistent across your website, Google Business Profile, and third-party directories. Inconsistencies, even minor ones like "St." versus "Street" or a missing suite number, reduce confidence that the AI is looking at a legitimate, verifiable business. This is the foundation. Without it, the other two categories are harder to build.
Legitimacy: 35 points. This is the heaviest category, covering review volume, star ratings, and license and insurance verification. California plumbers average 4.7 stars, which is a strong legitimacy signal on ratings alone. The review count data tells a different story. The average is 34.0 reviews per business, but the median is 0.0. That median means more than half of tracked California plumbers have no indexed reviews at all. A 4.7-star rating with zero reviews carries very little weight in a legitimacy model.
Readability: 40 points. This is where California plumbers lose the most ground. Readability covers website quality, JSON-LD structured data, mobile-friendliness, and page speed. JSON-LD is the critical piece: it tells AI systems exactly what your business does, where you operate, and how to contact you, in a format machines can parse directly.
Only 11% of California plumbers have implemented JSON-LD. The other 89% have websites that are readable to humans but largely opaque to AI recommendation engines. That explains the most striking number in the state data: 926 contractors, 48% of the total, score between 0 and 9 despite every single one of them having a website.
A website alone does not generate a Readability score. JSON-LD structured data does.
The plumbers vertical has the highest JSON-LD adoption of any contractor category in California at 30%, yet 70% of plumbers in the vertical still have no structured data. Those 30% with JSON-LD are pulling the vertical average to 47.7/100, well above the 21.5 state average across all contractors. The correlation is direct.
The top 10% of California plumbers average 67.3/100. That score is achievable when all three categories are addressed: consistent NAP data, a verified review base, and structured markup that makes the site machine-readable. Getting there requires closing gaps in all three areas, not just building a better website.
The Readability gap is the most fixable problem in this dataset. Structured data implementation is a one-time technical task, and it affects the category worth the most points. For most California plumbers, it's also the category where the current score is closest to zero.
Check where your business stands in all three categories at /find.
Score Distribution Across California
The score distribution is not a bell curve. It's a cliff.
| Score Range | Contractors | Share of State |
|---|---|---|
| 0–9 | 926 | 48% |
| 10–19 | 3 | 0% |
| 20–29 | 220 | 11% |
| 30–39 | 299 | 16% |
| 40–49 | 203 | 11% |
| 50–59 | 115 | 6% |
| 60–69 | 97 | 5% |
| 70–79 | 30 | 2% |
| 80–89 | 24 | 1% |
| 90–100 | 1 | 0% |
926 contractors, nearly half the state, score between 0 and 9. Only 1 contractor out of 1,918 scores between 90 and 100. The four tiers tell the same story: 55.3% score below 40, 32.2% land in the Fair range (40–59), 11.0% reach Good (60–79), and just 1.5% hit Excellent (80–100).
The average is 21.5/100. The median is 22.0/100. Those two numbers being nearly identical confirms the distribution is not being skewed by a small group of outliers. Most California plumbers are clustered in the bottom third of the scale.
How California Compares
California's 21.5 average ranks below most comparable markets. Texas averages 35.7/100 across 16,902 businesses. Ontario sits at 38.5/100. Pennsylvania averages 23.5/100. Florida, the closest comparison, averages 19.8/100.
Within California, plumbers as a vertical outperform every other contractor category tracked: 47.7/100 average, with 30% JSON-LD adoption. HVAC contractors average 33.0/100, roofers 31.0/100, and general contractors 30.3/100. Plumbers lead on both measures.
That lead exists because the contractors who implemented structured data are pulling the vertical average up. The other 70% with no JSON-LD are keeping the floor low.
The JSON-LD Gap
Readability carries 40 points, the largest single category in the scoring framework. JSON-LD is its most impactful component. At the vertical level, plumbers have 30% adoption, nearly triple the 11% California state average across all contractors. That advantage is real but limited: 70% of California plumbers still have websites that AI systems cannot parse for structured signals.
The median review count for California plumbers is 0.0. More than half the contractors tracked have no indexed reviews, even though the average rating among those who do have reviews is 4.7 stars. A strong rating without indexed review volume contributes almost nothing to Legitimacy scoring. That 35-point category is being left mostly unclaimed by the majority of the state.
City-Level Variance
The gap between top and bottom cities is 42.6 points, which is wider than the gap between a Fair score and an Excellent one.
Top cities by average score:
- West Hills: 46.8/100
- Canoga Park: 45.4/100
- Granada Hills: 43.4/100
- La Jolla: 42.0/100
- Reseda: 41.6/100
Bottom cities by average score:
- Marina Del Rey: 4.2/100
- Sylmar: 8.8/100
- Beverly Hills: 9.0/100
- Valley Village: 14.3/100
- Studio City: 14.5/100
West Hills averages more than ten times the score of Marina Del Rey. That difference doesn't reflect service quality. It reflects how completely those contractors have addressed Identity consistency, Legitimacy signals, and Readability infrastructure.
If you're in one of the lower-scoring cities, your baseline is not just behind the state: it's behind your direct competitors in cities thirty miles away.
Check your position against both your city average and the state benchmark at /find, or see how your market ranks in the full California plumber directory.
Action Steps
The scoring framework assigns fixed point values to each category. Prioritize by weight.
Readability: 40 Points
Readability is the largest category and the one where most California plumbers currently score near zero. Only 11% of contractors statewide have implemented JSON-LD, and only 30% of plumbers specifically. That means 70% of plumbers in the state's leading vertical are leaving up to 40 points unclaimed.
The single highest-impact fix: add LocalBusiness or Plumber schema markup to your website. JSON-LD structured data is how AI systems confirm what your business does, where it operates, and how to contact you. Without it, your website is human-readable but machine-invisible. This is a one-time technical implementation, and it affects the category worth the most points.
After schema, address mobile-friendliness and page speed. Both are Readability components. A site that loads slowly or renders poorly on mobile reduces your score in the same 40-point block that JSON-LD affects.
Legitimacy: 35 Points
The average California plumber has 4.7 stars. The median review count is 0.0. That combination, high rating quality with no indexed volume, produces almost no Legitimacy score for the majority of contractors tracked.
Two fixes apply here:
- Indexed reviews: Ask recent customers to leave Google reviews. Volume matters for AI scoring, not just the star average. Getting from zero to 20 indexed reviews is the highest-leverage move in this category.
- License and insurance verification: Unverified license status leaves Legitimacy points on the table. Confirm your credentials are current and visible on your website and profile. Verification status directly affects how AI models assess your legitimacy as a contractor.
The top 10% of California plumbers average 38.0 reviews per business. The bottom 50% average 19.0. That 2x review gap maps directly onto the 66-point score gap between those groups.
Identity: 25 Points
NAP consistency, your business name, address, and phone number, must match exactly across your website, Google Business Profile, and every third-party directory where your business appears. Inconsistencies that seem minor ("Ave" versus "Avenue," an outdated suite number, a different phone format) reduce AI confidence that the entries refer to the same verified business.
Audit your listings on Google, Yelp, and any directory where your business appears. Fix discrepancies before investing in the other two categories. Identity is the foundation: errors here limit how much the other fixes can improve your total score.
Combined Impact
The bottom 50% of California plumbers average 1.2/100. The top 10% average 67.3/100. That 66-point gap reflects what addressing all three categories looks like in practice. You don't need to reach 67.3 to see meaningful visibility gains: even modest fixes in any single category produce measurable score movement from a near-zero baseline.
Check your current score across all three categories at /find, or see how your market compares in the California plumber directory and the full California contractor state report.
Frequently Asked Questions
What is an AI Trust Score and why does it matter for my plumbing business?
An AI Trust Score measures how visible and credible your business appears to AI assistants that recommend local contractors. The scale runs from 0 to 100, built from three categories: Identity (25 points), Legitimacy (35 points), and Readability (40 points). California plumbers average 21.5/100. That score means the typical California plumber is not meeting the threshold AI systems use to surface contractor recommendations to homeowners actively searching for services.
Why do 926 California plumbers score between 0 and 9?
48% of California plumbers score in the 0-9 range despite every single one of them having a website. A website alone contributes almost nothing to the Readability category, which is worth 40 points. Readability requires JSON-LD structured data, mobile-friendliness, and page speed signals. Only 11% of California plumbers have implemented JSON-LD. Without that markup, AI systems cannot parse what your business does, where you operate, or how to contact you, regardless of how polished the site looks to a human visitor.
What does JSON-LD actually do for AI visibility?
JSON-LD is machine-readable markup embedded in your website that tells AI systems your business type, service area, contact details, and operating hours in a format they can parse directly. Among plumbers specifically, 30% have adopted it, well above the 11% California contractor average. That adoption gap explains why plumbers average 47.7/100 as a vertical while the state average across all contractors sits at 21.5/100. The correlation between JSON-LD implementation and score is direct.
My average rating is 4.7 stars. Why is my score still low?
Rating quality alone contributes limited weight to Legitimacy scoring. The median review count for California plumbers is 0.0, meaning more than half of tracked contractors have no indexed reviews at all. A 4.7-star average with zero indexed review volume produces almost no Legitimacy score. Volume matters as much as quality. The top 10% of California plumbers average 38.0 reviews per business compared to 19.0 for the bottom 50%.
How do I find out my current score?
Check your business score at /find or browse the full California plumber directory to compare your position against your city average and the state benchmark.