Where do Internet users spend most of the time, and how much?

A study report (Courtesy: Nielsen, a global information and measurement company) found that Internet users spend about 20-30% time on social network sites, than anything else.

People prefer personal computers more over ‘mobile web and apps’, for access to social networking sites.

About top social networking sites in the United States, Facebook scores higher than anything else in the social network.

With the growing popularity of Facebook and other, business marketers (and SEO companies like Web Technologies Inc etc.) prefer promotions mostly through social network sites.

Opinions any, about the growing trend of social networking sites?