It could become a natural extension, that as well as buying stuff -- take it out of the Kindle -- you could buy books, music, real-life products, appliances and goods and so on.
Логичным продолжением  станет момент, когда можно будет приобретать не только Kindle, но и книги, музыку, повседневные товары,  технику, продукты и так далее.