Twitter is reaching a significant milestone. At nearly 50 million tweets per day, the average output of Twitter users has climbed dramatically over the past year.

@kevinweil in his post on Twitter’s blog puts this in perspective. 50 million tweets per day equals roughly 600 new tweets every second. A year ago, average output was 30 per second. Looking back further, we get closer to Twitter’s very beginnings.

2010 – 600/s
2009 – 30/s
2008 – 3.6/s
2007 – 3.5/min.

It wasn’t long ago that Twitter allowed you to see a feed of all tweets on your Twitter home page. Anyone remember those days?

Looking at the graph above, one wonders what happened at the inflection point around April 2009. Was it the Ashton Kutsher/CNN race to 1,000,000 followers? Was it Oprah signing up for Twitter? Or was it a combination of elements creating the perfect storm?