February 14, 2005
PayPal alums Chad Hurley, Steve Chen, and Jawed Karim begin work on a "Flickr or HotorNot for video." They register youtube.com the next day.
April 23, 2005
"Me at the Zoo" — 19 seconds of Karim in front of the elephants at the San Diego Zoo — is the first video posted to the site.
October 21, 2005
Nike is the first major company to embrace YouTube's promotional potential. A video of Brazilian soccer star Ronaldinho dancing the samba with a ball is an early viral hit.
December 15, 2005
YouTube officially debuts. Two days later, Saturday Night Live airs "Lazy Sunday." The digital short attracts nearly 2 million views in a week and makes creator Andy Samberg a star. Two months later, NBC asks YouTube to remove the clip; it complies.
April 5, 2006
A day after Sequoia injects $8 million in funding, Judson Laipply uploads "The Evolution of Dance," a six-minute mashup of 50 years of dance crazes. It becomes the most popular clip in YouTube history, with 131 million — plus views.
October 9, 2006
Google buys YouTube for $1.65 billion.
July 23, 2007
YouTube and CNN host their first presidential debate, featuring citizen-submitted video questions. In the 2008 election cycle, 7 of the 16 presidential candidates announced their campaigns via YouTube.
April 11, 2009
Susan Boyle becomes a global celebrity after her audition on a British TV talent show is uploaded and viewed 80 million times. In December, her first album became the best-selling debut ever for a female artist.
October 12, 2009
YouTube passes 1 billion videos a day but remains unprofitable. Analysts estimated 2009 revenue of $240 million, but YouTube spent more than $700 million storing and serving all that video.