From comScore’s just-released  2012 U.S. Digital Future in Focus

Social:

Social Networking accounted for 16.6 percent of all online minutes at the end of 2011 and is on track to surpass Portals as the most engaging online activity in 2012. Facebook continues to lead as the driving force behind this shift in consumer behavior, accounting for the largest share of online minutes across the entire web in 2011.

Video:

More than 100 million Americans watched online video content on an average day to close out 2011, representing a 43-percent increase versus year ago.

Mobile:

At the end of 2011, more than 8 percent of all digital traffic was consumed beyond the ‘classic web’ via devices such as smartphones and tablets.

E-Commerce:

Total U.S. retail and travel-related e-commerce reached $256 billion in 2011, up 12 percent from 2010.