Forum Moderators: martinibuster
what I can expect in terms of CTR
Nope but I can nearly guarantee you will see a big increase if my metrics are anything to go by.
I love the look of the 728x90, however no one ever clicked on it, no matter what my site looked like otherwise or whatever the niche was about.
And I had the opposite experience, which just goes to show that testing is the only way to know what will work for a given site. Fortunately, it's easy to test ad sizes with AdSense, assuming that your ads aren't hardcoded into individual pages.