I just purchased an ipad and am a little confused about stores for ebooks. I know you can buy ebooks through the apple store, but notice there is also a kindle app available for the ipad. Aer there any difference between the way purchased ebooks are viewed on an ipad if downloaded on the kindle app vs ibooks from the apple store. Simply stated ...is one store better than the other, or are the file formats similar when viewed on the ipad. Thanks for your help!