Shawn
The jury's still out on whether it's worth it, on an hourly wage-equivalent basis.
In some cases, I've lost a small amount of money.
In other cases, I've earned as much as $3 for every $1 spent in AdWords (though there is obviously a point of diminishing returns here!)
And in many cases, I've about broken even (which means I actually come out slightly ahead, since I charge my AdWords account to a frequent-flyer-miles-earning credit card)
Is this a good way to make a full-time living? Maybe. But frankly, I've increasingly found it to be tedious and not very fulfilling.
BTW, please don't sticky me to ask for details on what specific affiliate programs I've been most successful with. This is, frankly, a case in which my time and effort and funding has been involved in testing various programs.
Remember that AdWords is just a source of traffic, just like email marketing, banner ads or generic search listings. And affiliate programs mixed with a good source of traffic (like AdWords) will obviously generate revenues.
So if you find good affiliate programs (that convert well), it is possible to make money out of AdWords/affiliate programs.
The trick is to find the right affiliate programs. And no ebook is going to tell you about the best converting affiliate programs. You need to do that on your own through trial and error. And if you are using AdWords to do that, it can hurt if you don't find the goose that lays golden eggs soon.
I actually do this, and have managed to turn a profit, but certainly not on the level mentioned in the ads. It requires quite a bit of tweaking and judicious management of keyword spending and ROI tracking.
But to let you know how its going -- I've done it since about May, and it still hasn't outpaced my day job, which is about 20 hrs a week with fairly low pay. It IS always nice to have a little money on the side, though. :)
Shawn