Originally Posted by NullNix
I look at all this complexity, and I think 'why?' (though reader synchronization may be a reason: I have only one). I just keep my unread books in an unread collection on the kindle, the read ones in a read collection, the being-read ones in an 'Active' collection (chosen to be near the start of the alphabet, since the PW always alphasorts collection names), and shuffle them from one to the other to keep track of them. If the Kindle gets full (ha! ha! nowhere near, give me a few years), some of the stuff in the read collection gets deleted and goes back to live in the clouds (if Amazon-bought) or in my calibre backup (otherwise, though I'm tempted to push all of those through personal documents email just so that *everything* can live in the cloud, for consistency).
This is simple and requires essentially no effort. It can't track what books I've already bought, though, that's true, but then that's a problem I already have in physical bookshops, and at least Amazon can often warn you that you already bought something.
It is a personal choice, I cannot advice it to other who have different tastes and habits. I read on two different readers, one for when I am out of the house, one when I am in bed. Thus Calibre to synch the readers. And the attribute helps in remembering.
The Excel spreadsheet, as I said, is more of a safeguard for my memory. In 12 years (I started ereading on a PocketPC) I have bought more than 1000 books, which, being made of bits, do not appear on my physical bookshelf and thus I need to keep track of them. I am also a fan for stats, therefore I also keep track of what I buy, and how much I spend.
That is all. Calibre would be enough for me ( a toast to Kovid and all the Calibre team, it has become indispensible for me) if I did not want to know what I am spending.