A Web-based search engine that indexes content specialized by location (local venues and activities), by topic, typically for consumers, or by industry, geared to businesses (B2B). Instead of returning thousands of links from a query, as is common on a general-purpose search engine such as Google and Yahoo!, vertical search engines deliver more relevant results to the user.
Also called a "vearch" engine, a vertical search engine may charge more per ad than a general, or "horizontal," search engine. People want relevancy, and the more horizontal search they do, the more they tire of wading through pages of superfluous material. Although users can always narrow their search to hone in on their desired result, vertical search engines do the narrowing for them.
Beware of Too Much Specialization
A vertical search site may not always index the Web for content, but may produce links only to proprietary content. It may be relevant, but highly prejudiced. See organic search results