Ghose's book "Tap" discusses how businesses can benefit from consumer data collected through smartphones and how mobile technology is shaping consumer behavior and the economy. Drawing on research from around the world, Ghose describes contradictory behaviors like seeking spontaneity but predictability. He identifies nine forces that influence consumers, such as time, location, and weather. The book explores how mobile technology wields influence over shoppers and represents lucrative opportunities for companies in today's growing mobile economy.