Here's what he has to say about why he is trying to make it with a search engine:
Search is one of best businesses on the Web. Search traffic monetizes really well. It can be 50 to 100 bucks per 1,000 page views (CPM). When I was the CEO of Topix, a local news aggregator, we were doing pretty well monetizing local page news, about three or four bucks per thousand. We were getting one dollar even on forums, and those ads are generally worthless. If you go to a social network like Facebook, CPM can be 15 cents. People aren't in buy mode. They don't possess intent to buy. But if you go to a search engine and type in "Palo Alto Real Estate," you've declared your intention to buy a house in Palo Alto. So real estate agents buy as many clicks as they can possibly get.
Our intent is to put search ads on the site. We can be a profitable company with far less traffic if you were running a local news site. $50 is much higher than $3.
You don't need a ton of traffic - you just need the economic conditions in place so that mainstream businesses, small and large, some of which have never dabbled in web advertising, are looking to get hold of your targeted traffic.