Starwood Preferred Guest (SPG) members can earn 500 Starpoints per stay, up to three stays (1,500 bonus points), when registering for the offer and using the SPG app to book a stay at Starwood hotels and resorts through March 31, 2015. You must pay with an American Express card to get the bonus points and all stays must be completed by March 31, 2015. Visit http://insideflyerus.wpengine.com/link/?11915 to learn more and to register for the offer.
Bottom line: Starwood is pushing their new app that can be used as your hotel room key at select hotels with SPG Keyless.