The Riverview Hotel is a deluxe four-star establishment. Late on Friday, it had 20 of its 300 rooms available when the desk clerk received a call from the Pines Hotel. The Pines Hotel made a booking error and did not have room for 4 guests (each of whom had a "confirmed" room). The Pines wants to send its customers to the Riverview but pay the rate the guests would have been charged at the Pines ($180 per room) rather than paying the normal rate of $300 per room at the Riverview.

If The Riverview accepts the guests, what will be the incremental revenue?