I had just that conversation with one of the founders of Cuil. Anyone remember Cuil? Search engine company, 2008-2010. They actually got it running, but not very well. I asked what the revenue model was. They didn't have a good answer. They ran out of runway before finding more investors or revenue.

Cuil was a nice demo, though. With under 100 people, they got a search engine going that did its own crawls and was roughly comparable to early Google. But this was before Google started to really suck, and there wasn't a market.

Google hired their key people to keep them off the market.