Do push notifications come over the data services, or is it more like an SMS and on carrier traffic? I'm tending to believe its data services, so for anyone who is a data user with iPhone... Do you think the $15/mo data plan when used sparingly will be enough. Or if you don't want to pay more (for additional data) are your push notifications cutoff until your next payment cycle? Or at least they would/should come over the wifi connections when you are available via wifi, right? Since push seems to work with wifi only devices like the iPad, iPod Touch if wifi only. What are your thoughts? I'm wondering if getting a family plan with two phones and share the dataplan between devices if the data is used up for a month will that reduce the usability for push to only wifi?? I think I've answered the question that it will only work with wifi but would love any opinions or experiences from other users.