How the smartphone can become a personal concierge (not a stalker) in the mobile marketing revolution of smarter companies, value-seeking consumers, and curated offers. Consumers create a data trail by tapping their phones; businesses can tap into this trail to harness the power of the more than three trillion dollar mobile economy. According to Anindya Ghose, a global authority on the mobile economy, this two-way exchange can benefit both customers and businesses. In Tap , Ghose welcomes us to the mobile economy of smartphones, smarter companies, and value-seeking consumers. Drawing on his extensive research in the United States, Europe, and Asia, and on a variety of real-world examples from companies including Alibaba, China Mobile, Coke, Facebook, SK Telecom, Telefónica, and Travelocity, Ghose describes some intriguingly contradictory consumer behavior: people seek spontaneity, but they are predictable; they find advertising annoying, but they fear missing out; they value their privacy, but they increasingly use personal data as currency. When mobile advertising is done well, Ghose argues, the smartphone plays the role of a personal concierge—a butler, not a stalker. Ghose identifies nine forces that shape consumer behavior, including time, crowdedness, trajectory, and weather, and he examines these how these forces operate, separately and in combination. With Tap , he highlights the true influence mobile wields over shoppers, the behavioral and economic motivations behind that influence, and the lucrative opportunities it represents. In a world of artificial intelligence, augmented and virtual reality, wearable technologies, smart homes, and the Internet of Things, the future of the mobile economy seems limitless.