googleblog.blogspot.com/2006/0 ...

Under the agreement with the plaintiffs, we are going to open up that window for all advertisers, regardless of when the questionable clicks occurred. For all eligible invalid clicks, we will offer credits which can be used to purchase new advertising with Google. We do not know how many will apply and receive credits, but under the agreement, the total amount of credits, plus attorneys fees, will not exceed $90 million.