If you have a Kindle you might be interested in these programs…
Kindle First (Prime)
Every month you get a chance to read one of four pre-release Kindle books for free.
Kindle Daily Deal
Every day 4-5 books are marked down (usually to 1.99). One slot is reserved for SciFi and Fantasy.
Discounted Kindle Books
Buy a discounted e-book copy (sometimes free) for any past physical book purchases. This depends on if the publisher has participated.
Kindle Owner’s Lending Library (Prime)
Borrow a Kindle book each month for free. This depends on if the publisher has participated.