Emma, My TA responded with a bit more detail, can't say I completely understand but here is the info I received! Hope it helps! "How the promotion works is every 5th room that books you get the 6th room credit (based on double occupancy) back so it has nothing to do with the nights it just means that if you had 20 rooms booked all with double occupancy then you would get back a refund on your credit card for the 6th, 12th and 18th room (pretend that the price is 50% room and 50% flight – since they do not break it down for us) so if it was $1500 per person then $750 per person would be for the room so in a double occupancy room there is 2 x $750 = $1500 so you would get a refund for $4500" Kari