I love Amazon. I buy everything there from books to groceries to electronics to clothes. Being something of a homebody it's very convenient. I particularly like when they remember what I bought and when. For example, I can answer the question "how long did that last case of tea bags last me?"
However, they remember books you've bought only by type. So if I bought the paperback version of a novel a year ago and then see it for the kindle, Amazon appears to have no clue that I already read it after buying it from them. I find that very annoying.
I know. I should be able to remember what I've read and what I haven't, but I read a lot of books and have burned out quite a few gray cells over the years. I started this list just so I could go back and see if I'd already read something, and even if I liked it. It helps but I think Amazon could do better. After all, they're using computers and I'm stuck with my aging brain.