This infographic put together by SEJ charts the use of the use of the prominent social sites since 2005 and gives us some more specific facts about the growth of a select few social sites over the course of the last year.
It also provides us with some random interesting facts. Apparently, there are 10.2 million comments posted to Facebook during the average 20-minute span in 2010. The number of companies using Twitter has also topped the 50% threshold.
Check out the full infographic below and click to enlarge:
Source: The Growth of Social Media: An Infographic