Aggregator (directory site)

An aggregator is a site whose product is other businesses' information. Yelp and Google collect reviews across every category. Angi, Thumbtack, and HomeAdvisor cover home services. Healthgrades and Zocdoc cover doctors and dentists. Avvo covers lawyers. Each holds a profile for thousands of businesses with roughly the same fields: name, location, services, hours, ratings, and reviews. That uniformity is exactly what makes them useful to an AI engine trying to compare options.

When an answer engine gets a question like who's a good orthodontist in Plano, it needs sources that list several orthodontists in Plano with comparable information. A single practice's website can't do that. An aggregator page can. So aggregators show up constantly as cited sources. In one vendor analysis of 267,280 AI citations drawn from its own clients' local-marketing campaigns, the SEO tool Local Dominator found Yelp, Google, Reddit, Facebook, and Angi were the most-cited sources. That's a convenience sample with no disclosed methodology, so trust the ordering more than the counts, but it matches what most local businesses see when they check their own answers.

Some aggregators have formal ties to the engines now. Yelp disclosed a data-licensing agreement with OpenAI in its Q4 2025 earnings in February 2026. Thumbtack was integrated into OpenAI's Operator in January 2025 and into ChatGPT for home-services booking in October 2025, though no data-licensing agreement was published. Reddit, which functions as an aggregator of opinions if not listings, has a licensing deal with Google worth roughly $60 million a year and a partnership with OpenAI estimated at roughly $70 million a year. Where the engines pay for data, expect that data to be read.

For a small business, this means your aggregator profiles are part of your website whether you think of them that way or not. A Yelp page with four reviews and no photos is a thin source; a complete Healthgrades profile is a strong one. Yext, analyzing 6.8 million citations across retail, financial services, healthcare, and food service, found managed listings like Yelp and Google Business Profile made up about 42% of AI citations. Not local-specific, but a clear indication that listings carry weight.

Which aggregators matter for you depends on your trade and on the engine. Tibly's cited-source tracking shows which directories each engine actually cites for the buying questions in your market, so you can complete the profiles that are doing the work and skip the ones nobody's reading.