There is a thread over at Jill Whalen’s High Rankings Forum I’ve been watching for just over a month now titled, “Google Base, Is anyone using it?” Like many other industry analysts, I closely monitor as many SEO and SEM related forums as possible in order to get as close a view as possible to how other search marketers think. According to the thread, few of High Rankings members are thinking very much about Google Base.

As I read through the thread, I was surprised to see that nobody mentioned any other vertical search engines. Last year, commentators were suggesting that the development of vertical search engines was indicative of an appropriate and natural fragmentation in the search engine market. In other words, tired of trolling through general search results when looking for something specific, users would turn to a search engine dedicated to serving particular niches.

This sort of thinking was shared by venture capital investment firms, some of which have threw tens, if not hundreds of millions of dollars in entrepreneurial start-ups trying to break into the vertical search market over the past three years.

The efforts of the vertical entrepreneurs and their big-money backers have, for the most part, proven unsuccessful. This is in part because the vertical search market is already occupied by some very big players, and in part because the vast majority of searchers continue to be satisfied with results pulled from Google, Yahoo, MSN or Ask.

It should be noted that the Big4 search engines have each developed their own vertical models. Results from Yahoo! Shopping, MSN Shopping and Google’s Froogle/Base, sometimes appear in general search results on their respective engines. The most extraordinary network of vertical search engines is the one associated with Ask.com’s owner, InterActive Corporation (IAC). IAC’s vertical search holdings include, local search tool CitySearch, The Home Shopping Network, Ticketmaster, RealEsate.com, Entertainment.com, Hotels.com and Reserve America. It also holds a controlling interest in Expedia.com.

Though competing against the biggest search entities and the user loyalty that sustains them is usually a path to subduction, some have survived to become the online equivalent of household names, branded destination sites. Many of the search appliances associated with Ask.com fall into this category.

Branded search engines are ones that directly serve information to searchers at a domain owned by that search engine. Well known examples include Monster.com the employment specific search engine, AbeBooks in the used-book market and Become.com and Shopping.com in the general product search market. As destination sites, these search engines receive visitors looking for very specific items. A person conducting a search at AbeBooks is clearly looking for a rare or used book. He or she is not seeking shoes.

Sometimes, as with the IAC/Ask.com stable of search tools, branded vertical search engines are used to inform other search engines, joining a wide array of rivals following a second type of vertical model.

The second model works in the background as an informative search tool or one that serves information to, or through other branded Internet entities. Earthlink, for example, uses vertical search engine WebMD for health related searches. Aside from lawyers, litigants and law students, most people access search information from niche engine Findlaw via a third-party such as CourtTv’s website. This is the area Google Base appears to be falling right now, as a secondary database used to add information to results at Google.

By serving specific segments of the overall search market, vertical search, as a model, shows a great deal of promise. Unfortunately, the best search appliances are only useful to search marketers if a large enough number of search-consumers use them. I don’t mean to say that vertical search is a dead end street, as it is not. It just hasn’t become the main-street thoroughfare predicted in 2005. Entry to the market for smaller start-ups has proven far more difficult than many anticipated with the 3 largest search engines creating or upgrading their own vertical applications and IAC forming its enormous vertical network.

Search marketers should pay attention to vertical search appliances and when doing so, look very closely at where results are distributed as well as how placements are calculated. There are important places to get placements out there and as the vertical market slowly grows, being in these places could drive that little bit of extra traffic that makes a good campaign much better.