As its profits continue to drop, McDonald’s is turning to targeted mobile vouchers in a bid to salvage brand loyalty and drive in-store traffic as other food brands such as Dunkin’ Donuts and Starbucks go from strength to strength with their mobile rewards platforms. The fast food chain has inked a deal with mobile voucher developer VMob, previously known as VoucherMob, to begin rolling out more mobile offers to its customers in the United States.