Fullscreen, the online content and influencer management company owned by Chernin Group and AT&T's Otter Media, has gone through a lot of changes in its short life. But the company's acquisition this week of influencer-marketing company Reelio shows the company is pretty clear about where brand marketing is headed.“The integration of Reelio’s platform into our network brings us one step closer to building a complete solution for the future of brand marketing, which we believe will be social-first and content-driven,” said Fullscreen GM Pete Stein in a news release."Social-first and content-driven." That sums it up pretty nicely.Brands will increasingly be creating content rather than simply trotting out the latest ad. They'll working more and more with influencers who know how to make winning content that's custom built for success on specific platforms. And publishers will be honing their relationships with both brands and influencers to make sure their audiences have satisfying experiences that will keep viewers coming back.The race for attention online will increasingly be driven by video. More bandwidth, and even more people (especially overseas) on capable smartphones will drive some of the continuing shift. More importantly, addressable TVs, ever more Smart/connected TVs, powerful new 5G mobile and Next Gen TV networks and related technologies will drive low-latency, super-fast connections to all kinds of devices.Content across those devices will be king, but really, only content that's constructed for social success will truly thrive amid the sea of choices crowding in for every viewer's attention.Reelio's units include one focused on cause-marketing campaigns, and another that allows brands to sponsor the pet-project campaigns of creators.Those are interesting slices of the influencer marketing space. But the real core of the deal is connecting brands and influencers, who know how to navigate the complexities of creating content for specific platforms. Reelio's platform is also, as Tubefilter put it, "informed by data science and proprietary technology." Navigating the space between data, artificial intelligence/machine learning tools, in-house human talent and platform knowledge will be key to success for companies in the transforming online world.And Fullscreen is far from the only company buying up influencer-marketing shops. Twitter bought social-media matchmaker Niche back in 2015. YouTube bought FameBit, another influencer-marketing company in 2016. Last year, Vemba bought Epoxy.TV, which provided influencers with tools for managing their followings.Most prominently, in January, the reviving Viacom, which has been reshaping itself under new CEO Bob Bakish, bought Whosay. With that acquisition, Viacom will be better able to help advertisers shape their branded content across all of Viacom's pay-TV and online properties, crucial if its TV networks are to remain relevant amid the current video revolution. Whosay is best known for its work helping celebrities manage their followings and relationships with brands.Regardless of whether Reelio can realize those same benefits for Fullscreen, expect to see more of these kinds of deals as content owners, publishers and brands all try to navigate a new, social-first world where content you care about is spotlighted by influencers, AI and other tools.