Not necessarily. I had a few bad experiences with vWorker, freelancer and other market places. oDesk is slightly better than the lot. In oDesk the initial 30 days was working on low priced contracts and couple of times with clients who didn't pay. It was a little painful learning.

But, then I got a little better at identifying the right set of clients and now the I set rate at $33/hr and most of it in hourly contracts that are guaranteed payment. I also take fixed price contracts from clients with whom I have existing relationship. Many guys I know are charging $60/hr and having a good practice.

The thing in the initial phase you come across a lot of noise and as you find out the 1-2 good clients from the 10 shabby ones, you get repeat business from them.

The difference between freelance marketplaces and direct sales is that in the former the clients have a real need, while in the latter the we have to convince the potential leads of the need to have a good website with proper attention to typography, speed and ux.