According to AccuStream Research, online video viewing occurring across professional, user-generated content (UGC) and social networking channels, destinations, multiple screens and platforms cleared the 511 billion mark in 2012, a 20.3% annual increase.Professionally produced, hosted and managed video advanced 17.9% to 104.4 billion. UGC/social networking channels, which are increasingly populated with pro and semi-pro publisher branded channels, saw total volume rise 21% to 406.8 billion.Mobile, tablet and connected device related views averaged 13.2% across the professional realm of sites, while UGC, led by YouTube, tallied an estimated 22.2% mobile total.Professionally managed sites publishing episodic programming content published by broadcasters, cable networks and syndication partners captured a 22.5% cumulative viewing share, up from 8.3% in 2006.