Native advertising formats -- ads that mimic the native non-advertising content on a publisher’s page -- now represent more than a third (35.7%) of all advertising sold by social media outlets in the U.S., according to new estimates released this morning by media marketplace analyst and forecaster BIA/Kelsey. The analysis, which is an update to its U.S. Social Local Media Forecast, projects native formats will rise to 42% of social media spending in 2017. "Display remains the most prevalent form of social advertising throughout our forecast," states Jed Williams, vice president-consulting at BIA/Kelsey. "At the same time, native advertising formats are quickly emerging as alternatives to display that can generate better engagement and performance. The rapid growth in native is further accelerated by the widespread usage of social networks on mobile devices." The update estimates that native formats rose 77% from $1.4 billion in 2012 to $2.4 billion this year, and will expand more than 20% per year over the next four years to nearly $5 billion in 2017. During that same period, conventional display ads in social media will rise at a compound annual growth rate of 12.6% to $6.8 billion in 2017 from $4.3 billion this year.