I've interacted with several vendors who use these sound boxes. The article is a bit misleading in the sense that illiteracy is not the primary driver of the usage of these devices. It is a better check-out experience. Vendors were busy and annoyed by the fact that they have to use their phone to confirm payments which often hindered them from doing their routine to sell more stuff. Think about vendors making street foods, actively selling vegetables, etc.
Now all they have to do is listen to the confirmation, directly streamed from the payment gateway vendor's server as soon as receive the money. Minor convenience, agreed, but the service isn't expensive to run (thanks to the minimal hardware it needs and the low data prices in India) and surprisingly even small vendors are okay with paying a subscription fee for it.
Now all they have to do is listen to the confirmation, directly streamed from the payment gateway vendor's server as soon as receive the money. Minor convenience, agreed, but the service isn't expensive to run (thanks to the minimal hardware it needs and the low data prices in India) and surprisingly even small vendors are okay with paying a subscription fee for it.