maximillianos - 3:00 pm on Feb 17, 2010 (gmt 0)
For us, it is more of the reliability in terms of payment of those offering affiliate programs.
This is a good point. We have wasted countless months testing various affiliate programs only to find they don't pay out, and those that do often retract payments weeks or months later.
With Adsense, I know what I made by the end of the day.
But I agree with everyone who says "it varies" for everyone and every site/niche. I have a few sites that Adsense does awful on, but affiliate programs did better. Smaller sites that are highly targeted I think lend themselves to affiliate programs better if you can match them up with one or two good products/programs. At least for small one man shops like me where time is a valuable resource.