The term “search engine” refers to a software program that searches the Web and Usenet groups to find documents containing one or more specified keywords, and returns a list of documents in which the keywords were 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.
We see from the study above that horizontal search can’t always do the job. Clearly this is what is driving the quietly exploding vertical search revolution.
But what really is the limitation? The problem is that search engines often do not know what you want based on your search query. For example if you type in “diabetes”, the search engine does not know if you are a doctor looking for research data, or a patient looking for treatment information or tips on managing the disease. Slly, say a dentist is looking for information on ceramics, a common material used in dental work. If the dentist performs a Google search on the keyword “ceramics”, Google will serve up millions of results, but most of the entries on the first few pages will concern hobbies like pottery. On the other hand, if the dentist performs the same search on a Vertical Search Engine, it will return much more relevant results.
Search engines are trying a number of initiatives to address this problem, such as search query refinements that allow users to focus their searches more quickly, such as Yahoo Shortcuts or the Google Onebox. However, these refinements are not entirely scalable, as it requires human editorial input for each query to make them accurate.
Vertical search engines address this problem by allowing the custom design of search engines for a specific purpose. The human input is built in from the beginning, and is provided by motivated people who are not on the payroll of the vertical search engine platform provider. If you decide to use a search engine which says it’s a “health information search engine for doctors”, instead of one that is labeled a “health information search engine for patients”, you have already helped to reduce the ambiguity of your search queries even before you type in your query.
In addition, traditional horizontal search engines cannot always determine the target audience of a page or site. Vertical search engines naturally address this issue, because the sites included in the results have been selected according to more specific criteria, and perhaps even by human input.
So what does this mean for the world of search engine marketing?
Traditional SEO link building will get you nowhere for any custom search engine built on the vertical search platforms, because they rely on humans to decide which sites to include. Among the many vertical search engine start-ups that do not use one of these vertical search platforms, there are some that do their own crawls of the Web. Traditional SEO should help here, although the nature of the algorithms they use will vary from engine to engine, and may not be at all link-based.
Vertical search engines that match up with your business will most likely offer you a higher conversion rate than a horizontal search engine, since users will have implicitly self-selected themselves as interested in your vertical. PPC campaigns with these search engines should fare better as well. It should prove worth the effort to seek these vertical engines out, and develop a relationship with each one individually.
Advertisers on vertical sites are able to reach potential customers who are much closer to making a purchase decision than the average user on Google or Yahoo.