Lynn got me thinking in my "elmer fudd" (money making) thread, and I started posting about Google Adsense there. Then I scratched that and decided to start a new thread.
Lynn has talked about researching expensive keywords and building a content site around it. As it turns out, I already own a few sites that include some of the most expensive keywords--online casinos, gambling, etc!
But I won't use Google AdSense on these sites! The reason? Because I've been taking my sweet time building relationships with my members, subscribers and visitors. They TRUST me and my recommendations. (Believe me, the online casino industry is a little yucky, so it's nice to have someone to trust.)
Now imagine if I started using Google AdSense on this page, and "Casino Scam 'Em" was advertised on my page. Yikes! My members aren't Internet marketers, they're gamblers! So they don't know about Google AdSense. They may assume that I am somehow promoting a scam casino! Either they will lose respect for me, OR they won't know it's a scam and get ripped off! And I don't want to make "dirty money" like that.
Here's a somewhat equivalent example: Imagine if Stephan Ducharme showed up on your marketing site. Yuck.
The second reason (other than my reputation/credibility) that I won't use Google AdSense on my gambling sites is because I can make more money with their affiliate programs (lifetime customers) then with clicks. This is of course an assumption because I haven't tested it...but I guess I won't be testing it because of what I mentioned above.
HOWEVER....
Having said that, those gambling clicks are still lucrative. So for someone who isn't interested in building relationships or getting really involved in a gambling site (i.e., working with the casinos directly, etc), building a content site around gambling might be a good idea.
AND FINALLY...ANOTHER FLIPSIDE...
With the potential for abuse, would YOU want to be a Google AdWords ADVERTISER? This is an experimental time with AdSense, so it wouldn't be a really good time to experiment with PPC ad campaigns until a few of the kinks may be worked out.
Sure...it's possible that your campaign will do really well because your ads are sitting on highly targeted sites.
OR...you could have a lot of clicks and no sales because of fraud...or perhaps your ads are sitting on sites that haven't been able to monetize their traffic, so they're resorted to getting paid for clicks (by that I mean that their traffic consists of freebie seekers who browse but don't buy).
Ok, I'm done.
I just thought I would play Devil's advocate and look at the other side. 
Cheers,
Becky
