Single use voucher code / Gift voucher code
Set up a single use or gift voucher code that can only be used once to incentivize the guest to book direct for their next stay.
Maurice Martens commented
Should be easy to implement.
Kevin Obschlager commented
Very good idea, PLUS very important, the code should be only valid vor one guest, i.e. you should be able to assing all guest a single yous code.