Aditya Agarwal asks an interesting question and then answers it in the context of Facebook. The answer in this case is yes, and the logic behind it is pretty good. In his own words ” … searches carried out on Facebook had a particular structure that only we could understand and optimize for.” This does not preclude the use of other engines or APIs, but to deliver the results they wanted, Facebook’s answer was to roll their own.

However, in most cases, this is not going to be the case. One of of the headlines that always gets my goat is anything that has “Google killer” in it, since chances are that it is not even close to that. Too many people think that making the next great search engine is the way to fame and fortune, but even an engine better then Google is not going to necessarily displace it. What we need is a quantum leap, something that makes Google look like it was written in prehistoric times. Till then, the only people writing their own search engines should be people focused on vertical search or specific site-related search.