When Nook 1 was first announced, it had the following
main advantages over the incumbent Kindle 2 — PDF support,
ebook lending (even if it was / is just a token feature), library book support, replaceable battery, LCD touch - screen at the bottom, millions of free books from Google (although you could convert these for Kindle), ePub support, Chess and Sudoku, slightly better screen contrast, memory card slot, both WiFi and 3G.