For years, most Web teams have designed for the desktop. Mobile, if it even happened, was a port off the desktop version, designed and built before anyone even considered the mobile experience. This made perfect sense for a while. Browsing the Web on mobile phones was painful; carriers controlled access to the Web on their devices; and mobile network speeds made everything often grind to a halt. But things have changed so dramatically over the past few years that starting with the desktop may be an increasingly backwards way of thinking about a Web product. Designing for mobile first can not only open up new opportunities for growth, it can lead to a better overall user experience for a Web site or application. In this presentation, Luke Wroblewski will dig into the three key reasons to consider mobile first: mobile is seeing explosive growth; mobile forces you to focus; and mobile extends your capabilities.