Poor T-Mobile stil isn’t getting the iPhone. This is most likely due to T-Mobile’s data network, which will not be compatible with the iPhone 5’s 4G LTE. While AT&T and Verizon celebrate the bonanza that is sure to be the iPhone 5, T-Mobile will be stuck selling less-popular Android and Windows Phones.

Still, T-Mobile has a plan. The company is launching a campaign to lure iPhone users to its network by doing a little math for them. T-Mobile pointed out on its Issues & Insights Blog today that buying an unlocked iPhone 5 and bringing it to T-Mobile’s network will actually save money in the long run, compared to AT&T’s new shared plans. With T-Mobile’s new truly unlimited data plan, it really does seem to be a good deal – if customers can afford the upfront cost of an iPhone, that is.

Starting on September 12 (the same day as the big iPhone 5 announcement), T-Mobile stores will have unlocked iPhone demo units for their sales people to demonstrate to customers how to set up their own iPhones on T-Mobile. In addition, T-Mobile announced it was developing iOS versions of software such as T-Mobile myAccount, T-Mobile Visual Voicemail, and T-Mobile TV. Select markets will also gain access to test incentive offers for iPhone owners.

Unfortunately, T-Mobile’s 4G LTE service is not fully implemented yet. iPhone owners who go to the carrier will have to weigh how likely their city is to get LTE service soon. T-Mobile’s iPhone-compatible 4G HSPA+ service is already live in some cities across the U.S., though its speeds might not match those of 4G LTE.