New forms of vertical search are becoming increasingly important. Areas that the search engines have already embraced include local search and mobile search. In addition, voice recognition–based search is an area in which all the major engines are actively investing.
Local search was an active business before the advent of the Internet, when the Yellow Pages as supplied by your phone company were the tool of choice. As the World Wide Web gained prominence in our lives, the Yellow Pages began migrating online. These types of local search sites have subsequently evolved to leverage more of the unique nature of the Web. Some of the major players are CitySearch, Local.com, and Superpages.
As the major search engines developed, they integrated sophisticated mapping technology into their systems, and then began to map in local business data as well. Some of that data came from the same types of data sources that drive the Yellow Pages websites, such as Acxiom, InfoUSA, and Localeze. You can find these local search engines at http://maps.google.com, http://local.yahoo.com, and http://www.bing.com/maps.
One of the big challenges facing the local search engines is map spam—the proliferation of spam results in local search. Here are URLs to two articles that provide examples: