What is the most transformative trend facing the world of travel? As with so many other consumer-oriented industries, one of the biggest trends is the move towards mobile. Travelers are using their mobile devices for everything now, from research and booking to ticketing, getting customer service, and, of course celebrating or complaining about their experiences after their trips are over. In fact, mobile devices now generate more than 25 percent of all digital travel transactions made in the United States. And the trend is growing. The march towards mobile is one that consumers are embracing wholeheartedly. Understanding how to successfully answer this trend is one of the biggest challenges -- and opportunities -- for marketers worldwide.