Baen's done a number of hardcover books shipping with CDs containing dozens of free ebooks. When I bought the hardcover copy of War Of Honor back in '02, it came with a CD containing all the other Honor Harrington books up until then, and about two dozen other ebooks.
There are maybe five other science fiction series I probably wouldn't have taken a chance on (and purchased books from) without that CD.
The ePubs are digitally watermarked, and downloadable only eight times, but if you pull off a successful download, you can put it on as many devices as you have access to, at least, that's how I read the PaidContent article.
Admittedly, not as easily as buying it in the iBook store or the Kindle store. And there's the whole potential "If we find your copy out for share, we'll retaliate against you" angle.
I imagine iTunes gets ranked lowly because Apple doesn't want you searching for music through Google. Apple wants you searching for music through iTunes apps or desktop applications, and everything about the iTunes web presence points to that.