Hi Oliver, I would go with the suggestion of using pictures or screen capture in real time (Camtasia is great for this) and if you have some bucks to spare Viddler, is great as it has many features in which your customers can be "called to action" on numerous occasions throughout your video. Don't just rely on youtube or metacafe to promote with, take advantage of all the major video sites - vimeo, yahoo etc. because keep in mind that some people simply prefer using those sites versus others. And finally, make sure your keywording is extensive and very descriptive, you'll have much better results. Oh and one other thing, if the video is specifically targetted, ensure you have a user account (especially on youtube) just for those videos, keep better stats that way.

BTW here's a list of top ten video sites
http://video-share-review.toptenreviews.com/