Ferguson dominates.
Hajoca doesn't exist.
The $40B gap explained.
The largest private plumbing distributor in the United States operates under 60-plus regional trade names. AI engines have no idea who they are. Arcalea tracked 62 prompts across four platforms to document who wins when contractors search in AI, and why the answer is almost always the same company.
AI + SERP
names in market
prompts tracked<
high AI query
Entity fragmentation is the
silent killer of AI visibility.
Arcalea maps every distributor by its AI composite score against its Google search presence. In this industry, the quadrant a brand lands in is almost entirely determined by one variable: whether it operates under a single unified brand or a collection of regional trade names.
Ferguson Enterprises is the only distributor in this quadrant, and by a significant margin. 1,750-plus locations under a single nationally recognized brand, with a citation footprint in trade press, contractor forums, and directories that AI engines can reliably extract and attribute.
SupplyHouse.com is an online-native distributor with content structured for AI extraction: product comparison guides, FAQ pages, contractor-facing explainers. It earns AI visibility that substantially exceeds its physical branch footprint, proving that content architecture matters as much as market scale.
Several Tier 2 regional distributors hold strong positions in their geographies: F.W. Webb in the Northeast, The Granite Group in New England, Keller Supply in the Pacific Northwest. They earn local Google rankings but generate limited AI citations because their entity footprint doesn't extend to the national citation sources AI engines index.
Hajoca and Winsupply, two of the three largest distributors in the country by location count, fall here. Both operate under regional trade name portfolios. AI engines accumulate citation weight at the brand level; when that brand doesn't appear consistently, citations scatter across dozens of regional names and no single entity reaches recommendation threshold.
21 distributors. Three tiers.
One clear pattern.
The index tracks 21 distributors across three tiers: from the four national dominants down to fringe and online-native players. Estimated AI visibility is based on initial prompt discovery runs; full composite scores are in the complete report.
| Distributor | Tier | Notes | Est. AI Visibility |
|---|---|---|---|
| Ferguson Enterprises | Tier 1 | 1,750+ locations; single unified national branb |
High
|
| Hajoca Corporation | Tier 1 | 450+ locations; 60+ regional trade names obscure parent entity |
Near Zero
|
| Winsupply | Tier 1 | 660+ local companies; Noland, Carr Supply, APCO brand fragmentation |
Low
|
| Reece USA | Tier 1 | Formerly MORSCO; brand transition in progress; Sun Belt focus |
Moderate
|
| SupplyHouse.com | Online Native | No physical branches; structured content earns outsized AI citation |
Moderate-High
|
| F.W. Webb Company | Tier 2 | 100+ locations; strong Northeast brand recognition |
Regional
|
| Keller Supply | Tier 2 | 70 branches; Pacific Northwest market leader |
Regional
|
| The Granite Group | Tier 2 | 60+ branches; New England focus |
Regional
|
| Additional Tier 2 + Tier 3 | Various | 13 more entities tracked; full results in complete report |
See report
|
Three structural facts about this market.
The commercial plumbing distribution AEO landscape has a simpler structure than most industries. The reason is also simpler: one brand made one decision that compounds every year it goes unchallenged.
Hajoca is the largest private plumbing distributor in the US by location count. It is also nearly invisible in AI-generated answers to contractor sourcing queries. The reason is structural: AI engines build entity models from what they can reliably attribute. When a brand operates under 60-plus regional names, no single entity accumulates the citation weight needed to surface in AI recommendations. Ferguson made the opposite decision, and it shows in every platform's output.
SupplyHouse.com has zero physical branches and is not a market leader by traditional distribution metrics. It is an AI Darling, a brand that wins in AI-generated answers because its content architecture is optimized for information extraction. Product comparison guides, FAQ pages, and structured pricing explainers give AI engines exactly what they need to cite a source. Physical distributors with strong brands but weak content structure are vulnerable to this dynamic as AI search adoption accelerates.
Of Arcalea's 62 prompts, 13 are local-intent queries: best commercial plumbing distributor in [city], contractor accounts near [metro]. These prompts represent the highest-opportunity category for Tier 2 regional distributors: prompts where the national default answer may not apply and where local brand strength, content depth, and citation footprint can displace a national player. Regional distributors that ignore national AI visibility can still build a defensible local AI position.
The queries contractors ask
in AI that they don't search on Google.
This is a low-search-volume B2B vertical. Most commercial plumbing distribution terms register under 100 monthly searches in Ahrefs. But Arcalea's research documents commercial contractors using AI platforms to ask sourcing questions that they don't enter into Google, making AI the primary intelligence channel for a significant share of vendor evaluation queries.
21 distributors ranked.
Full entity fragmentation analysis.
Local prompt breakdown.
The complete report includes all 21 distributor composite rankings, the full platform-by-platform breakdown, entity fragmentation analysis for Hajoca and Winsupply, local metro prompt results across 13 cities, and specific AEO implementation recommendations for distribution marketing teams.
Questions about the index and the data.
Yes, and at a faster rate than most distributors realize. Contractors, facility managers, and GCs are using ChatGPT and Perplexity to ask vendor comparison questions that have low Google search volume precisely because the buyer bypasses traditional search. Arcalea's 62-prompt set is built from documented contractor AI query behavior, not from keyword tool estimates.
Entity fragmentation. Hajoca operates under 60-plus regional trade names. AI engines build citation models at the brand level; when no single entity name accumulates enough citations across trade press, forums, and directories, the parent company effectively doesn't exist in the AI answer layer. It's a solvable problem, but it requires a strategic decision to build parent-brand equity.
Content architecture. SupplyHouse.com's product pages, comparison guides, and FAQ content are structured for AI extraction in ways that physical-first distributors have not prioritized. AI engines don't know how many branches you have; they know what they can extract from your content and cite. SupplyHouse treats its website as a primary sales channel, and that investment compounds in AI visibility.
Local prompt dominance. Of Arcalea's 62 prompts, 13 are geography-specific: best commercial plumbing distributor in [metro], contractor accounts near [city]. These are the prompts where regional brand strength, local content, and local citation depth can outperform a national default. Regional distributors that build local AI visibility create a defensible position even if they can't match Ferguson's national citation footprint.
The composite blends six metrics across all four AI platforms: Entity Mention Frequency, AI Share of Voice, Position Power Score (first vs. buried), Platform Consensus, Recommendation Rate, and Prompt Coverage Rate. Scores range from 0 to 1. The model is the same across all three Arcalea AEO Industry Index verticals, enabling cross-industry comparison over time.
The Commercial Plumbing Distribution AEO Index full report is available now via the form above. It includes all 21 entity composite scores, the full platform-by-platform breakdown, entity fragmentation analysis, local prompt results, and implementation recommendations. Report delivery is immediate, no sales call required.