Yes that's possible,people are earning there by digging a particular article a lot of times so that that article will come to the front page of Digg & hence get lot of traffics.The site owner then pay to the diggers.But it's just like spamming & sometimes caught by Digg & hence banned.
In the last 6 months I've seen the hype for Digg die down quite a bit. People aren't selling their Digg services like they used to. I think Facebook and Twitter are taking that heat away from Digg.
That's right. And, if you are the owner of a page which gets lots of traffic from digg, then there are chances to convert them into sales.
ctually i think duigg is sort of bookmark. You can mybe get some traffic from there which in turn can boost your ad earnings but it hasnt been very effective for me.