Q: Why can't we mark books as READ, when searching books, once we sample it we should be able to mark as read!

I have read books all my life, now using IBooks, Kindle, etc but am increasing frustrated by having to sample books and not having the capability to mark these books as read. I have purchased books, thinking, hot dog, I have a new book to read, only to realize I have already read the darn thing. Once I get to that point, the whole book comes back to me so I just purchased a useless book.  The first of you electronic reader to allow us to track books we have read not only in your store but in our lifetime will win my forever business!