You can get significant SEO advantages by posting properly optimized videos on Youtube and many other free video sharing sites. In fact including web video in your promotional program has many benefits:

There is an excellent list of resources for producing and using online video on Ralph Wilson’s Web Marketing Today. Follow this link: 
Video Marketing Resources
It seems odd to me that Wilson mentions two important web hosting services, but does not mention the free web-hosting services provided by the major video-sharing sites (such as Youtube, Revver, etc.) [...]

Here’s how we harness the power of online video to promote your product or service…
First, we create video features that have broad general interest. These are short features approximately 2 minutes long. Some of these are “news” items, some are “commentary”, some are “tutorials” others are essentially articles turned into videos. The object is to [...]