It's interesting how Google is adamant about how you use AdSense, but they don't mind breaking their own rules for AdWords. Anyway, luckily I stopped the ads before it became too expensive, but I can honestly say THEY weren't the majority of my sign ups. :)

Your suggestions on a newspaper ad is great. I actually have been looking into it.

I hadn't thought about the radio exchange. I'll look into that also.

Thanks for the great tips.