They have to keep up with the gaming consoles: they introduced achievements for apps last year, I think.
On the consoles it's a way to prod "achievement whores" to try out the video apps.
Amazon's Freetime (for kids) has been handing out achievement badges on Kindles for a while.
http://www.amazon.com/gp/help/custom...deId=201384490
Anything that gets people to read or listen to books is hardly bad. And if giving out attaboys helps...
(Shrug)