Twitter referrals to videos on every major category of destination resulted in longer viewing times than any other traffic source. A Twitter referral to a music video averaged a 2:33 viewing time compared to 2:01 of time spent by people coming from Google.
Tweets drove viewing sessions of 1:52 on broadcast locations, but traffic coming from Facebook, Bing and Google were all in the 1:37 to 1:38 range. The exception to this rule was Tweets landing on newspaper sites, where Yahoo! customers viewed one second longer than Twitter refers.
Still, it is an interesting exercise to ponder
why a Twitter referral would tend to stay more engaged. Clearly the
social affinity aspect is at play, because Facebook refers, while not
quite as high, are also stronger in engagement than most other sources.
After all, a refer from a friend compels a viewer to watch longer, if
only to "get" what the friend wanted you to see in the video or just
because your social graph can target your tastes even more effectively
than a straight search.
The full report is available at Brightcove [PDF].