Seth Godin is a legendary marketer. In this article he examines how online video can be used by corporate marketers:
TV advertisers are finally discovering that YouTube + viral imagination = free media.
The good news for you is that money is not a barrier, which means that marketers of any size can play. But the rules are different, as they always are online.
Because media is free but attention is not (this is flipped from TV world) you need to make a different sort of ad for a different sort of audience.

