Well, that is actually not true. My example of an ebook I bought for around $25 - $50 was published by a guy who was making about $20k/month at the time he wrote it. When I contacted him and purchased it he was making closer to $50k and building a new house with the earnings. Sometimes it's not just about the money. Many people like to have their egos stroked. Unfortunately my sites which were making very good revenue with adsense are not anymore so I need something and hopefully this is it but I can't find a single review or any 3rd party information about this ebook via search engines or other forums. So I think I am just going to buy it. I'll let you know what I think in a few hours or in the morning if I fall a sleep.
Ok I did find a review: http://www.problogger.net/archives/2006/05/19/six-figure-adsense-publisher-shares-how-he-did-it/ From the above article it appears the ebook/videos are more for newcomers to adsense.