PPC Campaign Question

I'm interested in starting a PPC campaign for both of my websites. However, I don't sell anything on either of my sites. They both basically offer free information and resources and I make money through ads like Adsense, Adbrite, etc. I realize it's going to take some trial and error to see what works best, but do any of you PPC experts have any pointers on how to get the most out of it. My goal is to obviously make more money through my ads than I am spending on my PPC campaign. Thanks in advance!

You should read up about "ppc arbitrage" for some ideas and for some mathematical formulas that will help you with your campaigns. The basic premise is that you should have high paying ads, such as Adsense or an affiliate offer running on your site, and your source of traffic should be cheap. So that you will probably have to open accounts on the less expensive networks such as YSM, Miva etc. rather than on Adwords. You can take a look at a site like ppcpays.com for a list of various inexpensive PPC sources of traffic.

Very interesting. I will check out that site. Thanks for your reply.