why? First time to meet this case. Does it mean impressions cost? (for me, only a few hundred impression a day) Thanks!
Please read evertything here before asking more questions. http://www.webmaster-headquarters.com/faqs/adsense.shtml#What are CPC ads versus CPM ads
You are being paid for CPM ads I mean for the impression of the ads , it doesnot require clicking on them
It's called CPM. Been around for nearly a year now I believe. You get paid per impression by some advertisers.
I never knew AdSense has CPM ads, only CPC ads. Is this something new with Google or as part of a Beta test?