I've been using WiFi-only iPad for a few years and make/receive phone calls over WiFi and understand that you can do this with the cell models too. My question is what is source of the data-only restriction on the iPads is cell data capability? Is it marketing decision from Apple, a restriction from cell providers, or some other consideration? It may seem naive of me, but I cannot find a discussion of the reasoning of this restriction anywhere online. I must not be looking in the right places, or asking the right questions.