Apple said Thursday that it has shipped over 450,000 iPads since the device went on sale this past Saturday, spurring 3.5 million app downloads for the new tablet device by its earliest adopters.
Jobs also updated with 600,000 downloads of iBooks. The first day sales of books was 250k, so it’s keeping a bit above 1 book per device. First day apps was 1 million, so the app attach rate is now 7.8, well above the 3 from day one. Keep in mind that the iPhone attach rate grew to over 50 so it’s early days to see how iPhone compares to iPad as an app magnet.