You’ve read all of your free items this month. To register, get added benefits and unlimited access to articles, Become a Member. Already a Member? Sign in. Advertising Age Article Abstract L'Oreal, Walgreen's Look to Measure Effectiveness of Mobile Coupons Ad tech startup Sparkfly is helping the megabrands track consumers from mobile apps to point of sale. By John McDermott, Published on July 25, 2013 4 Want more Access, Content & Connections? Upgrade to Membership. We are glad you are enjoying Advertising Age. To get uninterrupted access and additional benefits, become a member today. Become a Member Already a member? Log in.