When Virgin Mobile USA service was acquired by Sprint, many Virgin Mobile users who were dependent on unlimited data plans were reassured that would continue. But that’s turned to disappointment now. Virgin prepaid users are going to experience throttling starting in October. Until then, Virgin Mobile users can enjoy the unlimited plans with no throttling.

This decision by a company owned by Sprint may raise questions, as Sprint is always campaigning about true unlimited data plans. There may be two explanations of this step. First, Sprint does not believe that they can find success with Virgin Mobile’s business with ambitious unlimited data plans. Second, perhaps Virgin Mobile is the test case for Sprint to observe the user reaction before they start doing the same throttling to Sprint data plans.

Technically the data plans will still remain ‘unlimited’ for Virgin Mobile users. The only change will be decrease of speed after reaching the usage limit of 2.5GB per month. If a user uses up 2.5GB by the middle of the month, he will get 256kbps till the end of that billing cycle. The actual speed they are advertising is from 600kbps to 1400kbps. Now there are two options for the users who do not use Sprint. Either they can be stuck on a slower phone for the rest of the month (T-Mobile and Virgin) or they can pay extra money for exceeding the usage limit (AT&T and Verizon).