The best opportunity for their product is with knowledge workers in highly paid positions who do a lot of information gathering. That's where their biggest value proposition comes into play. But there are serious problems. But for search, it's using resources people care about very much. Going through documents takes up memory.
People are very loath to use something if it's going to interfere with their word processing.
People who downloaded the application would be expected to pull their own weight and assent to becoming a referrer whose Web history would be searched in network queries. But Pandango promises a system that is both nondemanding of individual's computing resources and incapable of violating anyone's privacy. We don't look through people's hard drives like Gnutella or Napster. It's just a limited amount of information about their Web behavior. On top of that, it's fully anonymous for both requests and results.