According to the Pew Internet & American Life Project , 19 percent of Internet users now say they use Twitter or another service to share updates about themselves, or to see updates about others. This represents a significant increase over previous surveys conducted in December 2008 and April 2009, when 11 percent of internet users said they used Twitter or another micro-blogging service. Three groups of Internet users are responsible for driving the growth of this activity: social networ