I run a fairly busy forum with about 15,000 impressions a day. I know click thru rates on forums are notoriously low, but trying to maximise what I have.
I have a 728 leaderboard both top and bottom. The top ad attracts about 10 times more clicks than the bottom ad does.
However, I often notice that the average click thru value of my bottom leaderboard ads is higher than the average click thru value of my top leaderboard ads.
I really dont understand smart pricing, or even if this is an issue here. But if I remove the bottom ad altogether (and with it subtract the 15,000 impressions with the poor return that page gives) might that make my top ad more productive in terms of price per click, by delivering higher paid ads?
Obviously, I could try it and see but would like to understand some of the science behind this.
I tried this as well but only saw less clicks and return, so I do not think this will largely affect your return per click. However did you consider adding a 468x60 under the first post in threads? I get 70% of the return from the leaderboard on top through there, so... you might try this as well.
Note that this might affect the number of clicks on the top leaderboard but the return is higher when you add both results. Worth a try really.