According to the Business Insider, Facebook is NOT the largest social network on the Internet. Nope. It is NOT the largest social network. If you want to be able to reach the greatest number of Internet users, you would need to use.....
....yes you got it right, the good old Email.
It so happens that this is one of the oldest tool on the internet. I can still remember being given my first internet email account when I was an undergraduate back in 1981. It was an account created on the DARPA network at MIT. I was able to receive email messages from across the continent, California. In those days, the email was basically ASCII text messages, without all the embellishments of graphics, gifs or flash animation.
Now, in 2013, email is still being used as a primary tool in communication, whether social, commercial or on government business. I expect that it will remain the primary tool as well as choice for communication over the Internet for many more decades to come. Typed text is very compact, unlike video or sound files, which take up a bigger chunk of bandwidth.
Long live EMAIL!!