I'd say: start talking about books (while making sure the ereader is always there to be used, filled with books...) Read the books you know he'd like, so you can talk about those (without spoiling, naturally!) and whet his appatite, so to speak. If he doesn't get curious and won't even try to get started on those books, then let him be, it'll be a lost cause.
Usually, when we women want something, we'll get it anyway, just keep nagging long enough! That's how we got to buy that roadster last year 
And now he wouldn't want to get rid of it!