It's a nice idea that people could simply start themselves up as a tour guide for x (Oxbridge dons apparently make good beer money touring colleges and quoting Coleridge)

However like a lot of these connect the world to one person ideas, the money is scant. They even admit most of their revenue will come from hotel bookings - so despite the YC, despite the new paradigm for marketplaces and providers, it's just a new hook for Hilton hotels.

I have a sneaking suspicion that vast amounts of the value and wealth being created by the Internet is effective unmonetisable - affiliates and ads will only stretch so far.