Digg: Sponsored by StumbleUpon?
This was a brilliant move by StumbleUpon! After you click through on the ad they have a very slick video on how easy it is to place an ad with their service. By the way Reddit has a similar program too with sponsored links.
BTW If you've come here via Mashable, Digg or Reddit here's the tech section of my blog: www.fanboy.com/tech