The only ads I see on reddit (outside of AMA and some fairly suspiciously-timed posts about a certain brand that happens to be releasing a new product) are either at the top of the page as a sponsored post, or ones at the side about some ridiculous Lambeosaurus or "instead of an ad, here's a penguin".

Seriously, what's the deal with how much advertising they do for /r/dinosaurs? Am I the only one seeing this?

I've had okayluck with ultra well targeted Adwords ads, better than reddit. I've done site takeover style ads with buysellads.com which has worked out pretty well but it's expensive and hard to do when you're just starting out.