What changes from trade to trade

On November 7, 2026, we asked ChatGPT, Gemini, Perplexity and Google AI Mode two questions for each of ten trades in ten US cities: “What's the best plumber in Denver, CO?” and “Can you recommend a plumber in Denver, CO with good reviews?”, with the trade and city changed each time. That's 800 answers, 80 per trade, and we counted every site they cited.

What's the same everywhere

• AI cited about five sites per answer.
• Directories and review sites were 37% of what it cited, businesses' own websites 29%, best-of lists and rating sites 25%, and publishers 7%.
• 57% of answers cited at least one business's own website.
• Google itself, through Maps and Business Profiles, was one of the most cited sites in most trades.

What changes

• Which directories: Avvo and Justia for lawyers, Carfax and RepairPal for auto shops, Opencare and WebMD for dentists, Thumbtack and Angi for most home services.
• How much your own website counts: 38% of what AI cited for house cleaners, 20% for plumbers.
• Whether national publishers like Forbes show up: in more than a quarter of answers for HVAC, plumbing, roofing and pest control, and hardly at all for electricians or auto shops.

Each lesson that follows covers one trade: the five sites cited most, what that means for a local business, and what to do first.