How much will be spent on mobile advertising through 2021, and what will be the sources (and destinations) of those dollars? These are questions I’ve been tackling over the past few months.

Among the $72 billion projected for U.S. mobile ads in 2021, search will continue to hold the leading share, but it will be slowly overtaken by native social advertising (i.e. Facebook News Feed Ads).

That and several other factors driving U.S. mobile ad spending are broken down in the video presentation below. We’ll also publish the analysis in white paper form in two weeks. Stay tuned.