Twitter marked its 10th anniversary on March 21. On March 21, 2006, co-founder Jack Dorsey sent the first "tweet" from a prototype under development: "just setting up my twttr".
In a commemorative video, the company reflected on the past decade and expressed gratitude to its users with a tweet precisely 140 characters long.
(Click the image above to view the video on Twitter)

A 140-character tweet thanking the user appears at the end of the video