This is exactly it! I remember the time before these speakers became commonplace. You had to wait while the vendor checked his phone, argue if there is a delay in SMS notification, crowded environments meant waiting your turn and in general it was a very real hassle. With these speakers, you do the payment, yell out saying you have done it and go your way (async I/O :-) .
It is one of those small things whose impact is huge in practice. It is a lesson to us techie folks to always concentrate on the "real user experience" rather than imagined ones.
This is exactly it! I remember the time before these speakers became commonplace. You had to wait while the vendor checked his phone, argue if there is a delay in SMS notification, crowded environments meant waiting your turn and in general it was a very real hassle. With these speakers, you do the payment, yell out saying you have done it and go your way (async I/O :-) .
It is one of those small things whose impact is huge in practice. It is a lesson to us techie folks to always concentrate on the "real user experience" rather than imagined ones.