I 'used' it once when Sainsbury's first introduced their self checkouts, for some reason it asked me to do it after I tried chip+pin. Didn't work. Ended up hav

I 'used' it once when Sainsbury's first introduced their self checkouts, for some reason it asked me to do it after I tried chip+pin. Didn't work. Ended up having to pop outside to the cashpoint to get analogue money out. I assume it's just one of those old weird technologies that just exists because solely it's not been removed yet like fax machines