updated 12:40 pm EDT, Fri July 22, 2011
T-Mobile offers $10 micro SIM card for iPhone 4s
T-Mobile, which doesn't offer Apple's iPhone itself, is now offering a micro SIM card for compatible and unlocked GSM smartphones. The card, while free, requires a two-year contract and thus means T-Mobile subsidizes the card's $10 purchase price. Usually, two-year contracts are accompanied by a hefty smartphone subsidy.
Last month, Apple began selling unlocked GSM phones in the US, which is likely a big reason why T-Mobile is now offering the SIM option. A 16GB version costs $649, while a 32GB version is $749. Micro SIMs will also make it easy to use T-Mobile for data, although current iPads don't support its 3G and are relegated to EDGE data.
A handful of other devices, such as upcoming 3G and 4G versions of the Samsung Galaxy Tab 10.1, also recognize micro SIMs but are relatively rare outside of Apple.
The iPhone has been unusually popular on T-Mobile USA even without official support. As many as one million unlocked iPhones sit on its network. Apple's move to micro SIMs curbed that until now since T-Mobile wasn't prepared to support these users with the smaller cards.