I had a logo designed by a design firm last year tha cost me $600. I got 4 logos to chose from, from the design firm and I really didn't like any of them. The revision process was pretty well dictated by the them. It was one person's ideas, renditions etc...
With 99Designs, I got 389 designs from 109 designers to chose from and then I was able to work with my favorite designers for small improvements. I'm very impressed and I will be back and will reccommend to others! Need I say more?
Jason S.