A division of Google, and nothing else but a bunch of thieves. They offer to advertise on your site, and give you a share of mulah
, letting your money build up. Then at the apex of your financial glory, they disable your account and "refund your money to the affected advertisers." AKA, you get jewed
. Typically, they send you an e-mail with a bullshit reason saying your account is generating a risk of invalid activity, which may "financially hurt" advertisers (as though it will even scratch their surfaces). Google even has the nerve to say "thank you for your patience and understanding". Users are typically offered appeal forms, however, at the risk of not getting reinstated (or reinstated, then cancelled again) it isn't usually worth it.
Some people who have been shut down by AdSense have lost upwards of $3,000. Don't believe me? Then Google NCC Archives 219 and see what these happy people had to say.