Given the amount of inane gibbering that fills your Twitter timeline, it can sometimes take an age to scroll through all that... insight. But what if it was a real, physical, thing? How far would you actually be scrolling?
Obviously that's a little like asking how long a piece of strong is; depending on who you follow and how much they Tweet, it'll be shorter or longer. But hey, that didn't bother Randall Munroe of XKCD fame, so it shouldn't you, either.
On my computer's monitor, the average tweet is about 2.4 centimeters high... This suggests that Jeph Jacques' [author of Questionable Content, who has Tweeted 36,000 times] tweet tower is 900 meters tall—taller than the tallest building—and still growing...
According to an analysis by Diego Basch, as of last year the "average" Twitter account had tweeted 307 times and was following 51 people. But averages can be deceptive; most Twitter accounts had never even tweeted at all, or have only one follower.
Combining Diego's July 2012 estimate with the current rate of tweets per day suggests there have been a total of about 345 billion tweets as of October 2013. That means that if you followed every Twitter user, your timeline would be eight million kilometers high.