Hotels.com has a Welcome Rewards program that is free to sign up for. When you stay 10 nights at any qualifying Welcome Rewards hotel, you get 1 night free that you can use towards your next booking.
This is available at over 65,000 hotels worldwide and there are no date restrictions. This is perfect if you love to travel and want to save some extra cash. Just make sure that when you book your hotel stays that you are signed into your Welcome Rewards account to get credit for your stays.