I don't understand why everyone always assumes that owning a kindle=never buying another book again, or even getting rid of all your books 
I have a houseful of books.
I also have a kindle. (and kindle app on my phone, ipod and ipad)
I think it is marvellous. really bloody marvellous. I have over 200 books on my kindle, alongside my houseful of books.
the plus points of a kindle? ease of buying books - buy it, get it now (takes 10 seconds or so to download it). I have bought many many books that I would not have looked twice at in the shops - mostly becasue they were cheap, it has to be said, but most of them have been enjoyable reads.
It has been indispensable on holidays/weekends away. no more agonising over which good lenghty book to take, as I can have a whole library full.
It is not always cheaper to buy an ebook (all sorts of silly reasons why - ebooks are subject to VAT for a start), btu it is more convenient.
I have found it far easier to read big books in bed with a kindle - not as heavy, can easily hold with one hand, the kindle automatically saves your page when you fall asleep reading
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I wouldn't be without mine. I have bought fewer actual books over the last year, but the ones I have bought were because it was not available on kindle, or textbooks.