Here's some other potential differences:
95% of my reading is done in the comfort of my own home. Of that 5% done away from the comfort of my own home, I can't
remember the last time I finished a book and needed to pick something new to start. So I have no need to have all possible choices available to choose from on the fly. Mostly because I'm never on the fly: I'm at work or I'm at home--and those two places are about 8 minutes part.
Also, almost all the ebooks I own, I've already read. My next read usually hasn't been purchased yet. I finish a book and then go fishing around the internet for what I might want to read next. I don't really stockpile unread ebooks on any of my hardware. Mainly because I don't think any of it's in danger of being unwritten before I get around to wanting to read it. I mean, I'll catch a bargain every now and then, but for the most part, I don't buy an ebook I'm not ready to begin reading immediately.