just $10 more on T-Mobile, a customer would have unlimited data without the throttling that would be a possibility for $60 a month on T-Mobile's plan. Would a T-Mobile customer that uses a lot of data each month pay $70 for no-cap on data usage, or would he opt to pay the $10 less and hope that he doesn't go over the 2.5GB data cap at that price?
Additionally, T-Mobile customers would have to ask themselves if $100 is enough to make them switch carriers. Sure, there is no ETF with the new T-Mobile plan, but until the phone they purchased using the new EIP with the carrier is paid off completely, it remains locked to T-Mobile. That means that the $100 you're getting from Virgin Mobile would have to go toward the price of a new phone.
Suddenly, all that money that Virgin Mobile saves you over two years doesn't look so good after all.