May 2005: YouTube launches in beta
April 2005: First video uploaded, "Me at the zoo"
September 2005: First video to pass 1 million views is a Nike advertisement
June 2006: YouTube strikes a deal with NBC over SNL's "Lazy Sunday" video
October 2006: Google acquires YouTube for $1.65 billion in stock
July 2007: YouTube partners with CNN to host the US presidential debates
August 2007: Advertisements first appear on YouTube in the form of translucent banners
October 2007: YouTube introduces the Content Verification Program to cut down on copyright infringement
April 2009: Vevo finally allows music videos to be posted to YouTube
November 2009: Full HD (1080p) video comes to YouTube
October 2010: Dan Savage starts the viral "It Gets Better" campaign on YouTube
January 2011: Arab Spring activist videos go viral
October 2011: First YouTube-sponsored original channels launch, including Crash Course and SourceFed
July 2012: The Olympic Games are streamed live on YouTube for the first time
October 2012: YouTube algorithms are changed to favor watch time over view count. Let's Play channels like PewDiePie begin to be promoted and gain massive popularity.
November 2013: YouTube co-founder Jawed Karim weighs in on the new social direction of YouTube: "why the fuck do i need a google+ account to comment on a video?"
October 2015: YouTube Red, a combination of ad-removal and premium content offered via subscription, launches