Hey. I just made a post on ExoClick blog about improving CTR. It's mainly dedicated to ExoClick publishers but I believe that it will work for other networks too. Hope you like it. 1. Use ADs revelant to your content. It's pretty obvious but many of you after checking prices in Bid Esitmator Tool (it's a tool available from ExoClick admin area where you can check actual bids) for such niches like gambling or pharmacy (which are pretty high) put ADs from those niches even where they are not related to your site content. Don't do that. Your CTR will drop to really low level and you may earn less than you would put revelant ADs. 2. Use TEXT+IMAGES ADs. Text + Images ADs are one of the best ExoClick's features. With these ADs your CTR will be way higher than if you would use standard text boxes, because they catch user's eye and in my opinion they are simply looking good. Continue...
As I said I wrote it for ExoClick publishers but most of these points can be used for all PPC networks. A way better than yours. I hope so too. I will try to share my knowlage here from time to time.