If you put traditional (well paying) ads on Reddit, I think the userbase would revolt scream etc etc.
They'd scream, and there'd be a rash of "this sucks, I'm quitting" diaries and then like 5 people who were going to quit anyways would actually leave.
Look at their site, 2 total ads on the main page, one per comment page.
They could bump that to 5 per page without breaking a sweat. There's their revenue.
wouldn't even have to do that, right now their ads suck...they are either "hey pay us $20-$30 to advertise on reddit", thanks for not using adblock, buying some reddit schwag, yay reddit, and once in a while you see Amazon or some anime shows ads.
that's it...why can't they go to Honda and get them to pay them money to promote buying a Civic? or Coca Cola? etc etc/
I don't use AdBlock very much, but I must admit that the "thanks for not using adblock" message made me to promise myself that I'll never use AdBlock on reddit.
This way they'd get more or less guaranteed $3-4 CPM...the fact that reddit has 4 engineers and 0 sales people goes to show that they aren't even trying to monetize the site.