Crowdspring and 99Designs

So, one of my newest attempts at making money while sitting on my couch is to try out these freelance farms.  Crowdspring and 99Designs are both websites that allow companies to post projects and then designers do the work, submit their designs and compete to win.  The company picks the winning design and then that designer gets paid.  

Technically speaking, it is most definitely a way for companies to take advantage of designers by not paying them for their time unless they deem them worthy of the pay.  However, in a down economy setup, it is also a way for designers who might be a little down on their luck (i.e. me) to get some work and money that may have otherwise been just out of their reach.  Not only is this a way to keep yourself active and working, but to build your portfolio as well.  

But, what do you think?  evil corporate idea? or fun new way to create design?