I used to sell shareware on this site. I still consider this my business website, although it has pathetically little to do with my freelance business currently. I plan on changing that, but that's an issue for another time.
I've always believed that business websites should not have third-party advertising on them. You should be trying to sell your own product or service.
This site, will remain ad-free for the foreseeable future. However, I have created
a new blog about my weight loss attempt, and have decided to drop Google AdSense in there to see how it goes. I'm considering it an experiment. I'm not selling anything on that site, and a little advertising can't be all bad.