Part of our global social media forecast, this forecast estimates both the number of social media users in the US and the social media spending by the type of device: mobile and PC. We also segment social media spending by spending on in-feed ads versus out-of-feed ads on social networks. The report provides historical data going back to 2008 and a five-year forecast. To get a global comparison, please view the Forrester Research Social Media Forecast, 2016 To 2021 (Global).