I've seen this recently also, While new I'm not disappointed, It provides a next layer for not accidentally loading a paid app . Apple (yes I've said the word) does this with Itunes on the ipad. It may have evolved because of Android tablets, now with multi user space on tablets I'm not sure how the play store manages them but this may well have been in response to that. Tablets have multi users, so if one user (1) picks it up and say it was left on in the other users (2) space (usually family members) they don't buy a app under the 2nd user . Also you login to your tablet space so you'd want to ensure the app is loaded on the correct user.. It makes sense from some of what I've read but then it might be a bunch of hot air ... I'm sure someone will come along that knows for sure.