I have few sites with affiliate program reviews, getting about 400 daily visitors and I put there "popup/interstitial" with some clickbank products... but it looks like it is not selling much. Any ideas how to improve it or is there some more related product?

I need to generate some other sales because I am CDR status over one year and having over 500USD in clickbank waiting to be sent.

Here is the code: www.webmaster-money.org