If you either have a Kindle, or a Kindle Reader app, or are thinking of buying a Kindle, I would offer one piece of advice about the ebooks: Read the reviews. Don't just look at the 5-star rating.
The reason is that, especially with regards to ebooks which are priced above $10, quite often readers or would-be readers will submit a negative review based on nothing more than the price. Read their comments and you'll see what I mean. I've seen so many 1-star ratings where the entire body of the review comment is "I refuse to spend that much on an ebook". In other words: THEY NEVER READ IT. They're submitting a negative review without even reading the ebook/book. They just want to irritate the publisher. The net effect is that the author suffers, readers pass over a possibly great book, and the system is gamed. Sad. Amazon should include a rating criteria link so reviewers can choose categories like "price", "plot", "characters", "suspense" and so on. Until then however, you should be careful when passing over 1 and 2 star rated books.
Disclaimer: This does not apply to my ebooks because I have no ratings at all on them besides my own (one per ebook). So neeener-neener-neeeee-ner.