Advertising Age: The mobile ad spending pie is set to reach $100 billion next year, according to a report by eMarketer. This figure is more than a 400% increase from 2013, and it will likely double to nearly $200 billion between 2016 and 2019, accounting for more than a quarter of all media ad spending worldwide. Through 2018, companies in the U.S. are expected to continue spending the most on mobile ad spending, with those in China coming in second place.