If you invented a more efficient way to build an automatic transmission, I’m not so sure that the right response is to start a car company.

I’m trying to figure out why so many of the very smart people I meet who are trying to start search engines are building products I just have no interest in using. And I think what is happening is that when you have some idea about how to improve some aspect of search, it’s easy enough to start a whole search engine to show off your invention.

Last week, I met one of the those people, Anna Paterson. Ms. Paterson and her husband, Tom Costello, started Cuil, a search engine that openedto the public Monday morning...