A few weeks ago, I discussed vertical search engines - search engines that address a well-defined vertical market (a narrow topic with deep content) as opposed to, say, Google's horizontal market approach (the broadest possible range of topics with a shallow reach). The intention of vertical search engines is to add value by increasing the value of the search.
 
So what are the business models for vertical search engines? The key issue is who pays and there are three ways a vertical search engine can be monetized:

1. Listed sites pay.
2. The subscribers pay.
3. Advertisers pay.

The ideal formula would be to exploit all three revenue streams but whether that can be done depends on the nature of the content and the consumer of the service.

Consider, for example, a product from EDC called Legal Advantage (see editorial links below). This is a vertical search engine that "provides lawyers with client-oriented information specifically tailored to the way individual lawyers work."

The cost is born by subscribers and due to the nature of the content and the users, subscriptions are EDC's sole revenue stream. The reason that Legal Advantage is likely to be very successful is that it provides a single point of service that has been traditionally delivered through multiple industry services such as Westlaw, LexisNexis, and generic search engines such as Google.

Legal Advantage essentially brokers data from other sources and adds no human editorial processes other than those applied by their external suppliers such as Reuters. The focus is the tracking of one client's data - share prices, public financial statements, press releases, competitive market data, and so on - essentially a dynamic, in-depth profile of a company.

Now, as I pointed out earlier, the intention of vertical search engines is to add value by increasing the value of the search process, so rather than a horizontal search providing 900 hits with a 10% relevancy a vertical search a service such as Legal Advantage might return 100 hits with a 90% relevancy.

If examining a hit to determine its relevancy takes 30 seconds then 900 hits from a horizontal search engine will take 7.5 hours as opposed to analyzing 100 hits from a vertical search engine, which will require just 50 minutes. In both cases, we wind up with the same number of relevant results (90).

Mark Gibbs is a consultant, author, journalist, columnist and blogger.