Before purchasing a site, how can we make sure whether that site has been banned from adsense or not??
Usually not a certain website is banned from adsense but the owner of that account. I believe it's possible to use another publisher account at a website were it was banned by the former owner. When people are banned form the account there's usally something wrong/the matter. Search the forums, more answers to be found.. http://forums.digitalpoint.com/showthread.php?t=62973
I am pretty new to adsense so don't take my word as gospel. I believe the post above is correct. You use your same adsense ID on all your sites so it seems logical that it is the publisher not the site that is banned/black-marked. Colbyt