We’re just talking to a potential partner about implementing Direct Carrier Billing as a payment method - that is, someone presses “Put it on my phone bill” instead of “Pay By Card” and then with a fair wind and a following tide everything else happens completely automatically (picking up mobile account based on the connection data) with no data entry needed. (If the phone is connected via WiFi it can still work, they just send a text message with a PIN confirmation).
It costs more than card transactions (5-10%) but the argument is that it doesn’t cannibalise card transactions - that is, the people who pay by DCB are people who would otherwise not bother to purchase at all, rather than people who would have bought by card but choose to pay by phone instead (plus you can add the cost on as a convenience fee if you like).
I can see it working particularly well for / being very important for mobile transactions. Entering your card number onto a mobile is always annoying, and being able to check out without having to faff around finding your card is vital if someone is making an impulse purchase on the go (on which subject: this is why you should activate PayPal as a payment method too - talk to us!)
If you think you might be interested please let us know - either directly by email or reply to this thread!