Marketers are adapting quickly and learning to think about mobile first, as the outlines of how mobile users differ from PC users in their online behavior become clear, this article notes. For instance, mobile users tend to spend more time on social media, making them "the most engaged folks on social networks," observed Chia Chen, senior vice president and mobile practice lead at Digitas. "So the question is, how do we think about it from a mobile perspective in the beginning?" he asks.