Maybe because most people here never ever change their SIM card. You buy a phone and you're basically locked into your carrier until your contract expires, then

Maybe because most people here never ever change their SIM card. You buy a phone and you're basically locked into your carrier until your contract expires, then you buy a new phone because it's the only way to justify the ridiculous monthly fees. If you venture overseas you often just put up with the stupid-high rates your carrier will charge you because it's too much of a pain or too complicated to call your carrier and get your phone unlocked. I don't think saving mm's off the thickness is a factor at all because the SIM is still replaceable. I think Apple thought it was a better user experience to be able to choose their carrier this way. And of course now they don't have to stock iPads with carrier-specific SIMs. Yes, they could sell SIM-less iPads, but that would make for a poor buying experience, at least for us SIM-shy 'merkins.