Use vertical ads and not horizontal
Using vertical ads will bring you more hits, why? Because all traditional ads have been horizontal on internet, 468x60 banners being the pioneers, and people tend to ignore them which is called banner blindness. However when you put a vertical ad on your page "banner blindness" is not that high unlike horizontal ads.

Use text ads and not image ads
Banner blindness issue comes here as well, people usually don't pay much attention on the image banners. In this case it is proven that text ads perform better, their click-through is up to 5% while image ads click-through is less than 2%. So use text ads and get better click-throughs.