IDEA: Let customers continue to shop while waiting to check out: give them a numbered ticket as an option.
Do not make customers regret coming in your store just to stand longer waiting in line than the period of time that they shopped. Provide a numbered ticket machine near the front checkout lines that will provide a numbered ticket for the customer to take and hold until they are called by a cashier to check out (“Number 310 next please!”). This is an option and not required but since some customers detest to wait in a long line, let them continue to shop and spend more money while they wait for a cashier to call their number to come check out. It is up to the customer to decide to continue to shop (with a ticketed number) or wait in line (without a ticketed number).