[rootshelled]

You can't build something that can compete with Google without some very very deep pockets and lot's of data.

Same problem with niche search engines, unless they have some unique features/properties that Google doesn't have you are plainly better off with Google.

Google has a Monopoly on search, which looking at the market will hold up for the foreseeable future.

So unless you can offer a specific feature(set) for a niche or you just want to build it for the hell of it I wouldn't reccomend anyone to go into search engines.

I would probably go with what duckduckgo does but offer unique features that are usefull for one or more niches.