In all the wave of Windows Phone news recently, it may have missed your attention that Mobile Operator billing is expanding.
If a user is on one of the mobile operators listed below, the user can make Store purchases using their mobile account. Another way of making it easier for users to purchase Apps, Music and In-App purchase items!
See the current list here . This page will be updated as new MOs are added. Currently, it look like this:
The following table lists the countries/regions and mobile operators where Mobile Operator Billing in Store is currently supported. When you publish your paid applications to these countries/regions, Mobile Operator Billing will be offered automatically as a payment method for users of the specified mobile operators.
Data as of December, 2012
KT Corporation, LG U+, SK Telecom
Everything Everywhere Limited (Orange)
AT&T Mobility, T-Mobile USA