Nielsen this week released its latest look at which media giants are dominating TV viewership in the U.S., and once again, one company far outpaced all its rivals: YouTube. For the fourth consecutive month, Google’s video-streaming site accounted for more television usage than any other platform or media conglomerate, capturing a best-yet 12.5 percent of all viewing on big screens. While the 20-year-old YouTube is hardly an overnight success, its evolution from mobile-centric time-killer to a platform that battles Netflix and CBS for primetime eyeballs has been a more recent phenomenon. But it definitely was not an accident.