This tweet by Robin Sloan is apparently the 5 billionth tweet on Twitter. The number at the end of the tweet's URL is 5000000000, which likely means it is tweet number 5 billion if Twitter hasn't been skipping around.
The Social blogs that Robin Sloan has nicknamed the tweet, "The Pentagigatweet."
Corrected to show billionth not millionth! Thanks Glen Green
