NEW: Women in Their 30's and Young Driving Social Media

A new study by Netpop Research says women in their 30s and young people are the most active users of social media. The report, "Social Animals: Who's Sharing What and Why Online?," is based on an online survey of more than 1200 American broadband users 13 and older. The survey found about 73-percent of Internet users contribute to online content by way of various social media. Overall, 73 percent use a variety of social media. Microblogging on sites such as Twitter has grown a 400 percent since 2009.