Over the last few years, both AT&T and Verizon have been successful in changing their business model from giving unlimited data and charging for calling/texting to charging for data and giving unlimited calling/texting.
AT&T has been unsuccessful in kicking customers off their unlimited plans
AT&T eliminated their unlimited data plans for new customers in 2010. A year later, AT&T told those customers with an unlimited data plan that they would have their plans throttled if they consumed enough data to put them in the top 5 percent of the heaviest data users in a billing period.
T-Mobile’s UnRadio may NOT be available to all unlimited data plans
Recently T-Mobile CEO John Legere announced a free streaming music from several different streaming radio apps that would not count against the customers data plan. This exclusive was said to be free to ALL customers with an unlimited data plan and cost $4 a month for those with a tiered plan.
Sprint’s unlimited data won’t be so ‘unlimited’ after all, plans to start throttling speeds for heavy users
Sprint is soon going to be throttling their heaviest users in the company's most congested areas. Customers of both Sprint's postpaid and prepaid services, as well as their Boost Mobile and Virgin Moobile prepaid brands, are receiving notifications from the company informing them they'll soon face a new prioritization management scheme.