The document discusses the rapid rise of smartphone dominance. It finds that within 5 years, 71% of users will rely primarily on their smartphones for digital activities. Currently, 18% of users are considered "smartphone dominant" but this will grow to 57% within 2-3 years as the behavior spreads to all demographics. Three factors will accelerate this shift: 1) developing experiences for larger screens like phablets that see the fastest growth, 2) improving cross-device experiences as many users multitask across devices, and 3) adapting to trends in app replacement and innovation to drive continued app usage. Marketers must recognize this mobile-first environment and create integrated, cross-device strategies using formats like native ads that work