“Merchants are still slowly upgrading their retail point of sale (POS) systems to support various mobile payment options while new payment options keep showing up. No merchants have provided a complete list of payment solutions that their POS terminals support, neither do payment solution providers offer a complete and up-to-date list of merchants accepting their respective solutions. Consumers have to second-guess which payment option they could use. In a situation like this, a consumer usually uses his credit card instead.”, says Harry Wang, Senior Director of Research at Parks Associates.

From the article "The future of mobile payments – are there too many options that are confusing consumers and merchants?" by Scott Salaske.