From Beet.tv:

Online videos have a short shelf life, getting a quarter of their views within four days of being published, Brett Wilson, CEO of video distribution site TubeMogul, says. Content creators who publish a lot of video will have a better shot at success.

He suggests that content creators promote their videos hard for the first few days as attention will drop quickly.

Is your site producing enough video, or are you still doing hours-long productions praying for a hit?