You might be surprised to find how cashiers have their performance evaluated these days.
Did you ask if the customer found everything they were looking for?
Do you push an upsell option 100% of the time?
Do you successfully upsell a target percentage?
Did you ask if they have the company rewards card?
Did you ask if they want a company credit card?
Did you tell the customer how much they saved with their rewards card?
Did you mention the customer satisfaction survey on the sales receipt?

All while being timed.

In many retail outlets, cashiers will be terminated if they score low, particularly on upsells. Nobody in management gives a crap about how cashiers provide change.