I wonder what this means for e-ink sales?
Surveys in the US have suggested that about 10-15% of the adult population reads 12 or more books per year. And that 60% read at least one book per year.
I would assume that the 20% of the adult population who owns an e-book reader would include most of the 12-or-more group and the remainder would be people who didn't quite meet the 12 book cutoff.
But I would imagine that e-books sales will plateau as the remaining population without e-book readers ends up being less frequent readers. If you only read 4 books a year, for example, are you really going to buy an e-ink reader?