So, full disclosure that I work at oDesk.

We monitor the NPS, Net Promoter Scores, (a simple way to measure customer satisfaction) for all of our users and I'm happy to say that we are on the order of 80% higher satisfaction rates than benchmarks for the services industry.

As a hiring manager myself, I use oDesk to find, manage, and pay my distributed team of contractors that do sales, marketing, writing, and some web development. For me, it's almost like having drag and drop team creation. If I need a team for a new marketing project, I can hire resources quickly and easily and I'm not making any big commitments.