"Best Referrer: Stumbleupon"

What's this based on? I've tried StumbleUpon ads before. The bounce rate is insane. Approx 99.5%. It's basically useless for anything other than real-world load testing.

BTW, Reddit's new self-serve ad system is awesome. Dirt cheap, quality traffic, commenting on the ads to talk with your customers directly, and general Internet Bonus Points™.