You may want to try the tips that AFF gives you on the affiliate pages. The key is to alternate the ads, and yes, more ppl use pop-up blockers since Yahoo, Google and Atavista launched this in their free toolbar.
Also, check out the other affilate programs at
http://friendfinder.com/partners/
This company has been around since 1997 and pays on time.
If you target you traffic well, you should do well with them.
If you have any question email the affiliate team. I am sure they can help you...
- Butterfly