[sburud]

Good point! In the mobile space, a certain walled-garden platform traditionally killed off any app 10 minutes after you left it, and even to this date does not guarantee that your app will be allowed to call home on any semi-regular basis. This makes it impossible to guarantee delivery without using the officially sanctioned push system. And if we're doing push already, why bother doing it differently on other platforms? (even if they support cross-app coordination to make the polling battery-efficient)