Hmm, I actually had the exact same idea some time ago, but I didn't take it any further. It was just not worth it.
I'm sure we can all agree Digg traffic is worthless - no-one from there clicks on any ads (maybe it'd do for CPM campaigns but I'm not really into those). So what'd be the point? I mean other than being able to go around bragging about how you got a bagillion stories on the first page.