If you go here and enter information, Tor will send you (about) one free e-book a week.
Tor does science fiction. Granted, if you don't know that, you're probably not interested. But I've been signed up for a bit, and I receive their emails and their books, and I can tell you that the offer is legit. I will also tell you that the books are quality. This isn't a scam in any way, shape, or form that I've seen.