Earn 500 bonus Starpoints® per stay, up to 3 stays, when you register for this offer and use the SPG® app to book a stay at Starwood hotels and resorts with your American Express® Card, December 10, 2014, through March 31, 2015. All stays must be completed by March 31, 2015.
Then, use that same app to unlock your travel options — including your hotel room door at select hotels with SPG Keyless. Plus, manage your account, including adding your American Express Card, browse and book more than 1,200 hotels and resorts, and more. Learn more.
Must be a member of Starwood Preferred Guest to receive Starpoints. Enroll for free at www.spg.com.
ということで、12月10日より来年3月末までの宿泊予約をアンドロイドもしくはアップルのアプリ経由で予約し、且つ支払いをアメックスで行うと1滞在につき500ポイント、最大で1500ポイント（３滞在まで）が獲得できるそうです。
詳細はこちらにて。