It's an epidemic! Online video viewing soars among young web surfers

In fact, the number of people watching online video has nearly doubled since 2006, with 62% of adults saying they watched online video this year, up from just 33% three years ago.

The study said: "Over time, online video has become more deeply integrated into daily life, and has started move into the spaces that are typically reserved for traditional television viewing."

Overall, 19% of internet users say they use video sharing sites on a typical day. In comparison, just 8% of internet users reported use of the sites on a typical day in 2006.

While most of the content being watched is user-generated, there is also a growing archive of professional content available through YouTube and newer network-sponsored video portals like Hulu.

Efforts to lure viewers to these portals appear to be paying off, as more than a third of internet users (35%) now say they have viewed a television show or movie online.

In comparison, just 16% of internet users said they had watched or downloaded movies or TV shows when asked a similar question in 2007.

As internet users become accustomed to regular on-demand video viewing online, many are choosing to watch from the comfort of their couch.

Among those who watch TV shows or movies online, 23% say they have connected their computer to a television screen so they could view video from the internet on their TV. That amounts to roughly 8% of all internet users.

Watching online videos on sites like YouTube is more prevalent than the use of social networking sites - 46% of adult internet users are active on such sites, the study found.