99Designs is great for the bootstrap entrepreneur. You can state a rock bottom price and some designer somewhere will bid on it. You have better controls over your contest end date – say you get busy and need to extend your contest – you can do it in 99Designs but with Crowdspring you have to email customer support every time. I like the 99Designs contest interface better – it is easier to view and compare designs from one designer. Crowdspring's design view is too small, so if you have a large website design, you still need to have the designers submit an external link so you can hone in on the details.

Crowdspring is better for the enterprise level – you get templated contracts and NDAs. You can launch a private contest but this requires a minimum project cost, which ends up being US market rate, and prohibitive to bootstrap entrepreneurs. Crowdspring guarantees a minimum 25 entries or your money back, and appear to have a better system for alerting designers to your project, even if it is a private project, than 99Designs. In 99Designs, for private contests, you have to manually contact individual designers or no one will come.

I think both services could improve their designer search functionality – to be able to search designers by website versus graphic, and tags (green, sports, women's) will help companies better ID the right designer for their project.