JupiterResearch estimates that only 10% of Internet users have ever watched a full-length TV show online, as cited by MediaPost. The problem isn’t the audience though, it’s that there is little available to watch.

"The networks are only putting
limited libraries online," said Bobby Tulsiani of JupiterResearch. "The
consistency of the libraries and the user experience is still not the
way people want it."

Mr. Tulsani points out, for example, that only the first and the
most recent season of "24" have been available online — but none of
the interceding seasons.

Of those surveyed by JupiterResearch, 33% said being able to watch
any episode online for free was a key factor in watching online.

The report goes on to encourage TV producers to get over their fears
and look for new ad models. YouTube’s launch of semi-transparent ads is
one innovative example cited that puts the consumer ahead of short-term
revenue goals.

Via eMarketer