Do you have any idea how it ends up looking to your users?
There’s a great post here about measuring visitors video performance – do you know how often visitors end up with pauses while rebuffering? Should you be compressing your video more? Could you get away with higher quality video? How can you even find out?
Go read Simons post – it’s a bit technically specific to his Omniture SiteCatalyst analytics setup, but it asks some good questions and provides ideas about how and what you can measure to monitor your site’s video playback performance.