Cofounder of thumbtack here - left in 2010, which basically directly competes with taskrabbit now.

I can understand how you would be skeptical that there's much going on behind the scenes, but you have to understand that this is mostly on purpose. It SHOULD look simple from the outside.

But underneath, we're vetting, categorizing, and matching. How do you fill a request for house painting with a database of perhaps 100 house painters that are qualified? You don't want too many bids, but you want enough to give the customer a decent choice. How many leads to you send out to get, say, three bids?

It's all algorithms, and we've been working heads down on it for years and are getting pretty good at it. Not easy, though.