I’ve played with advertising on Eloquation and Squandrous in the past. While all my advertising experiments have been a relative success when it comes to making money, I really didn’t feel as though the Google Ads (or even the few ads bought directly) did much to enhance the experience on my site.
My rationale to get rid of advertising was based on the fact that the money I gained from advertising wasn’t worth the time and energy I put in and impact they had on my sites.
The real reason I don’t have advertising on my site? I’m not cool enough.