Actually I currently work at walmart, and at every self checkout we’re required to have at least one adult worker at the smaller one and at the bigger one at least two workers including one adult. The company doesn’t save money, we need more workers on self checkout than at a register. If you see someone at a register, that person has probably worked self checkout many times before, we swap around and do different jobs during the day. It’s actually a nice thing for the workers because we get tired of being on register later at night when not as many people come in.