One of the local grocery stores has a little drop box for people to write the name of their cashier on the ticket and drop it in the box if the cashier used their name (which of course was way more popular when checks were the preferred payment method). The cashier with the most tickets each month won something from the store.

Customer service wise, it's one of those things where some people don't care one way or the other, but those who do totally eat it up.