There is more competition than Kindle vs Ipad, what you are refferring to is Amazon vs IBooks. The hardware is a small marginal one time profit, if at all, while the buying of the books is a constant stream of cash. We all know that Amazon takes a loss on best sellers but it profits highly from second print editions and education. So for Amazon would they love to have everyone on a Kindle using their bookstore, absolutely. But if someone is going to buy an Ipad and would like to buy books from Amazon why not give them the avenue to do so?