Yes, you guys are right. If your keywords are too general so that non-porn-searching people or kids could see the results, then no advertised results are served. Likewise, I didn't even think you could buy a word like "bears," I thought you had to sexualize it or gay it up.

Also, I recently learned that even in the organic results, it's very difficult for a porn site to get a good ranking for a non-pornographic phrase. I'm still trying to figure this one out because for ages I could get nowhere with ranking for "hairy men," then a lot of the sites that ranked for "hairy men" had nothing to do with porn, now porn sites are back in the listings. I notice this changed within the last couple of Google updates.

cheers
dzinerbear