The $15 plan is no longer listed on the T-Mobile site's Prepaid Plans Page. The option to select the $15 plan has also been removed from the mobile (m.web2go.com) and desktop (my.t-mobile.com) versions of the T-Mobile customer self service portal.
A T-Mobile prepaid telephone support representative confirmed that the plan is no longer available to new customers or to current customers who are not already using it. Existing customers already on the plan can keep it indefinitely as long as they don't allow it to expire.
At one time the $15 monthly plan was heavily promoted by T-Mobile. I believe that it is still quite popular, especially with teens and parents.
It costs a mobile operator almost nothing to transmit text messages and very little for picture messages. I don't believe for an instant the T-Mobile was losing money on the messaging plan.
If you are looking for an alternative to T-Mobile's discontinued messaging plan, three good options are listed below:
|Operator||Plan or Package||Network||Technology||Monthly Cost||Voice min.||SMS||Data|
|AT&T||Unlimited Messaging||AT&T||GSM||19.99||0.10||unlimited||1¢ per 5 KB ($2/MB)**|
Update: I've seen several reports of existing T-Mobile prepaid customers who were allowed to switch to the discontinued $15 plan by calling T-Mobile customer support. So there is some grandfathering.