If we're all adjusting our votes, might as well adjust mine too.
I voted 3-5, definitely buying from 5 at least. But if Sony was an ebook store (which seems to be the case from some other recent responses) (and how do I not remember this one way or the other? lol) then I'm sure I bought from them when I had my Daily Edition PRS 950, which would make 6 at the least. But I'm pretty sure I bought at least a few from various small sites or publisher sites. I can almost swear I remember buying off a publisher, the Penguin site I think it was? Maybe one off a site like Vintage if they have their own store? I don't know, but the end result is I'm almost assuredly in the 6-20 range instead.