A conveniently meaningless term, isn't it?
Problem with places like this is that though they say "experts will always be in demand!" you can't find experts on such a site because they're drowned under a thousand incredibly cheap and ambiguously competent Asian and Eastern European devs touting the same wares.
I've never had any luck on such places, either as a buyer or seller... maybe I'm just doing it wrong. In the end, boring old networking of the old social type (y'know, the one where you speak to someone om real life) is incredibly difficult to beat.