It's a good opportunity to take advantage of this greed; the transaction fees discourage the people to use them.
Someone already made that, apparently.
You have some websites like Coinzilla, A-ads.com, Bitmedia, Cointraffic. You will have to choose from the CPC model to CPM. I would recommend choosing both. A CPC banner at the top of the page. A CPM banner at the bottom of the page... Always
This is going to be hard to pull off if you have less than 50K pageviews a month, since otherwise, you're not ranking high enough for the ad networks to be interested in accepting you. Well, except for A-ads, but I dislike that particular ad network because there are hardly any campaigns running on it, so the profits are extremely slim (since your site will be running empty banner ads most of the time).