I hope this forum doesn't take this as a stupid question but I noticed that many of you have more than one ereader. Why is that the case? I can imagine that one ereader has functionality that perhaps another one does not. But how do you keep your collection of books in order between one, two or even more devices? Just wanted to collect some feedback and see if there is a reason for me to purchase something above and beyond the Kindle I already have. Thanks for your consideration on this topic.