Not just many Social Media sites! There are many, many, many!
Here’s a convenient (and somewhat daunting) way of keeping track of ALL of them – check out “Conversation Prism 5.0”, the Visual Map of the Social Media Universe – here’s a link:
I count 28 separate social media categories each containing multiple social media sites. A great infographic of the social media universe. Print a copy and keep it nearby.
To take a look at how the Social Media universe has grown, click on the next link and scroll down to see the first version from 2008: