kindle unlimited does not contain everything but it does have a lot. the usa KU has the largest catalogue than anywhere else, which is why i snuck into it years ago.
the 10$/m fee changes if you get a 1 year subscription (33% discount) or a 2 year subscription (40% discount), which has to be paid upfront.
anyone who frequents this site's ebook section has to understand that ebooks don't magically and mysteriously appear out of nowhere - people have to somehow obtain them, whether "free" thru KU, thru overdrive, or an outright purchase.
the more popular authors, titles costing a fair amount - those generally do not end up in KU - but due to their popularity, they end up in the net fairly fast.
the downside of KU is the past few weeks i'm trying to get a title downloaded into k4pc (kindle 4 pc) and it won't work - i get an error message saying my version needs to be updated to get the title.
which i won't do because i need to have a particular highest version of k4pc along with a particular version of calibre with tools installed.
so if i update k4pc i can kiss goodbye the ability to remove drm.
as star999 notes, there is a limit as to how many titles you can withdraw at one time (i think now it's 20) and there's a "safe limit" as to how many titles should be withdrawn out of KU (i stop at 625 max).
while the bulk of this thread is from 2014, at least i've updated information.
see my other post for my explanation on why it's necessary to use a particular max versions of both calibre and k4pc:
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