Is video that important? I hate it when the only way I can understand what a product does is by spending 2 minutes to watch a video. Has anyone does tests to see how much video improves conversions?
My big point is, let people trust in and rely on a video as their first experience, make that experience priority, if it makes sense for your business.
ECM and Zumbox both offer very new strategies to dealing with a problem most people don't really conceptualize immediately.
What I can attest to is a video can really help get blogger coverage. Bloggers love to be able to embed a 1-2min demo of what your site is about. I believe it was a big part of what got us top coverage(on TechCrunch/digg etc.) when we launched few years ago.
Moreover, video helps you control the precise message in a world where bloggers can do a 5min writeup on your site that totally misses the point.