I've been on the fence for a long time on whether I should switch from iBooks to Amazon's Kindle app. Amazon does have more selection and you can technically view your books on different types of devices. But when I really considered my viewing habits, I couldn't see myself using anything other than an iPad to read digital media. That's not to say it is impossible that Amazon will ever come out with a better product than Apple in the future. They just have a really high bar they need to surpass in order to get people to switch. From what I can see Apple has a major lead on other competing companies and will continue to do so for a long time. Combine that with viewing options that are on par with the Kindle app and a book store design that in my opinion is much better than Amazon, I can't see myself switching to Kindle anytime soon.