The document discusses using location-based SMS marketing to drive customer engagement for various retailers. Examples are provided of campaigns run by McDonald's, Starbucks, Asda, Tesco, Sainsbury's, M&S, Coca-Cola, House of Fraser, Superdrug, and Tesco that targeted customers within a certain radius of store locations and provided offers to redeem in-store. The campaigns aimed to increase foot traffic, offer redemption rates, purchase intent, and brand recall for the retailers. Metrics like redemption rates and recall of messages are provided for some case studies to show the effectiveness of location-based messaging.