Coupons. Gift cards. Loyalty points. These tried-and-true tools of the retail trade might not be as sexy as other forms of marketing. But together they account for more than $165 billion in purchasing power ($110 billion in gift cards purchased, $48 billion in loyalty points earned, and more than $5 billion in product coupons redeemed). That’s almost as much as total e-commerce sales.

via The Coming Branded-Currency Revolution  – Harvard Business Review.