Vertical search, part of a larger subgrouping known as "specialized" search, is a relatively new tier in the Internet search industry consisting of search engines that focus on specific businesses. While Google, Yahoo!, and the like will continue to dominate the online consumer search market, research analysts say many specialized search engines are emerging to address the particular information needs of niche audiences and professions.

Origins of vertical search

Niche search engines are not new. Web sites that help users find people, shop and get business information have existed for years. But the number of these search engines being introduced has greatly increased in recent years.

In fact, in the last three years, research analysts at Forrester Research, Jupiter Research and MarketingSherpa have identified a new tier in search dubbed "specialized search", which includes "local", "topical" and "vertical" search. Local search is already a burgeoning subset, with Google Local and many newspapers offering this functionality.

Like consumers, businesses use the Internet for a variety of needs. Sometimes they’re looking for all the information they can get, and for that the likes of Google and the Yahoo search engines are used. But more often they’re looking for something very specific related to their businesses. That’s where vertical search sites come in. Vertical search engines deliver to businesses what the big sites can’t without the use of complex keyword combinations: relevant and essential content versus an exhaustive return of information.

Vertical search vs. broad-based search

To see how these sites differ, it’s helpful to know how they are designed. The term "search engine" refers to a software program that searches the Web and Usenet groups to find documents for a specified keyword and returns a list of documents in which the keyword was found.

Broad-based search engines such as Google or Yahoo fetch very large numbers of documents using a Web crawler. Another program called an indexer then reads these documents and creates a search index based on words contained in each document. Each search engine uses a proprietary algorithm to create its indexes so that, ideally, only meaningful results are returned for each query.

Vertical search engines, on the other hand, send their spiders out to a highly refined database, and their indexes contain information about a specific topic. As a result, they are of most value to people interested in a particular area; what’s more, the companies that advertise on these search engines reach a very focused audience. For example, there are search engines for veterinarians, doctors, patients, job seekers, house hunters, recruiters, travelers and corporate purchasers, to name a few.