Australia

I also got picked out for a random check a few times when I first started using it. After passing that process a few times, you seem to be trusted. I haven't been picked out in years, now.

I reckon at first it was probably making me do that about 1 in every 3 shops, which wasn't great. They definitely could have done a better job of making the onboarding experience nicer.

At a certain point I was getting frustrated with it and decided to start counting. After I started counting, I got checked 3 times out of 27 regular shops, and 0 times out of 11 "small" shops (which I defined as, very roughly, 5ish items or fewer, on account of the random checks asking staff to scan 5 items from your bag). Not sure how many times I had used it before I started keeping a tally, but I think around 20, and I think I was checked around 5 or 6 times.

If it had been up to me, I'd have made the first 3 or 4 shops almost guaranteed to not be checked for any new user, and then give them maybe a 1/5 chance for the next 30 or so shops, before easing off into what was apparently somewhere along the lines of a 1/10 chance or less. So you get an early good experience, but then get taught "hey, it is possible to get caught here" in a way that's a little gentler than what it actually was, but persistent enough to lock in that message.

The frequency with which I have problems with old-fashioned self-checkout certainly didn't hurt in converting me to this. Never once had it tell me I did something wrong like self-checkout does constantly. To me it just felt like "oh yeah, a routine random check". (And because it's a machine, I know it's actually random, unlike the "random" checks at airports.) The most irritating part was the fact that it was clearly used rarely enough that staff weren't on the lookout for people standing there awkwardly waiting to be scanned.