Use coupon code SUMMERVACAY, to get you $40 off the price of your booking at a participating Best Price Guarantee hotel on Hotels.com – when you stay for 1 or more nights (must spend a minimum of $300 for your stay). You must pay for your stay when you make the booking.
You may only use this coupon for bookings made between 12:01 am MT on July 15, 2015 and 11:59 pm MT on July 17, 2015 on the US version of Hotels.com for a stay to be completed between July 15, 2015 and September 30, 2015.
Go to this link for a list of non-participating hotels.
Here is a link to the promotion.