This document provides key social media statistics for 2013, including data on spending, users, and engagement for major platforms. It finds that social media is the #1 online activity and 8.4% of marketing budgets are spent on social, growing to 21.6% in 5 years. Facebook had over 1 billion active users and was the top platform for spending and engagement. Twitter had over 500 million users, with engagement higher for tweets with photos. Pinterest and Instagram saw strong user growth, especially among women aged 35 and under. YouTube reached over 1 billion visitors per month, with over 6 billion hours watched daily.