It depends a lot on the area. I run a moderate-traffic finance-related site that gets about $20 CPM via AdSense. (Before the financial crisis put an end to the glut of mortgage-related ads, it used to be more like $40.)
On the other hand, I run a music-related site that gets something like $0.25 CPM.
On the other hand, I run a music-related site that gets something like $0.25 CPM.