Quentin is a member of the Album of the Month Club and receives a new music CD every month without fail. The Club usually gives its members a time period within which they can reject the selection and stop shipment of the CD, failing which the CD will be shipped. Last month, Quentin received a CD from Album of the Month Club, a copy of which a friend had already gifted him. He had not found time to reject the offer as he was away. Quentin could not reject the CD and had to buy it. What kind of an offer-acceptance model does Album of the Month Club have?