Not only airlines are selling miles or points with a bonus discount, but also hotels. (current list below)
If you like to use your hotel points for a free night, but you haven't enough points in your account, this is might be a great opportunity to buy them for less than the usual price.
Buy hotel points promotions
Hilton Honors is offering a 100% bonus on points purchased by September, 30.
You can purchase up to 160,000 points pre-bonus per calendar year.
Marriott Bonvoy is offering a mystery bonus of up to 50% bonus on points purchased by September, 25.
IHG Rewards is offering a 100% bonus on points purchased by September, 09.