Following is an email reply from google. --------- Please be aware that publishers may not place AdSense ads on pages used as an alternate ad URL. As such, we kindly ask that you refrain from using this implementation. Please let me know if you have any further questions or concerns. Sincerely, Sandor The Google AdSense Team ----------- 01. is it alternate ad url against google TOS. 02. are they going to ban me if i continue to implement it.
Alternate ad URL is used when there's no releveant ad for the page available at the time, so no AdSense should be used there. You can try another CPC program for that.