TV is rapidly undergoing a fundamental change from a shared experience to a more personal one as a consequence of the proliferation of smartphones and tablets, BTIG analyst Richard Greenfield observed in a letter to clients on Tuesday. While there may be still be several people gathered around the living room TV, each is likely sitting with their own additional entertainment device -- meaning TV engagement is falling at an accelerating rate, he wrote. In just the past year, he observed, bandwidth consumption on mobile devices more than doubled to 20 percent of overall usage. The Rise particularly benefits cable operators, he noted, who control a pipe that is capable of delivering far more robust bandwidth than their DSL peers. YouTube, he observed, remains the No.1 destination for online video users, accounting for 17.1 percent of bandwidth usage, up from 14.8 percent a year ago.