Any book that claims they have the SECRET and wants to charge you for it should definately be ignored. They are like Linda says just "pushing buttons" on the newbie affiliate marketer to spur sales.
Want to know the SECRET for free?
The SECRET is to actually get involved and stay consistant at marketing one product or service. Don't be one of those people that jump from product to product looking for that big score immediately.
Its been said, and I believe it to be true, that 99% of all affiliate marketers fail because:
A) they never act on anything they are read or taught. They either procrastinate and put off doing anything till later, and soon forget altogether so they never act. Or...
B) and this is the biggest mistake of all, they jump on a new "fad" market and hope to get rich immediately when they don't they jump ship to another "fad". Soon getting discouraged and quit altogether.
Most all of these ebooks you can buy are just rehashed info from someone elses ebook that you can probably get for free somewhere. Want a good place to look for free ebooks? Try
SureFireWealth you can get a totally free silver membership there that will give you access to 100s and 100s of free ebooks that many people today are rehashing and selling for $27 - $97
Are there ebooks worth buying? Yes there are. But most of them are of the "instructional" and "how to" variety. And with the advent of Jonathan Leger's $7 secrets script many of them are dirt cheap now.
Affiliate marketing is tough and not an immediately lucrative career. I've been doing it for years and still only average $100 - $300 monthly. And yes I spent a ton of money on ebooks at first. I rarely ever buy one now and I always check
$7 Offers - http://www.7dollaroffers.com first before I buy any ebook.