This is a pointless distraction from the issue at hand but most free e-books are thinly veiled ads themselves. Their objective is to get you to pay for the author's products or seminars or whatever. It's quite different from the discussion here.
Not really. I've read some fiction ebooks that were self-published by authors and some were good. None had advertising (at least I haven't noticed), some had a suggestion to donate, but that's another story.
Also, if we can say the comparison with software is valid, there is a lot of software (of various quality from a total trash to exceptionally good stuff) that comes gratis and doesn't try to sell you anything.
