When you said:
"I should make a screencast showing how I use the product"
I think you should have made one as this would have opened up the opportunity to many others. Allowing them to learn how to use Camtasia and start creating screencasts.
In fact, I decided to pick up where you left off.
I have created a Camtasia Studio 4 tutorial and put it on a CD set:
I'd be happy to send you a review copy, if you would like one.
We are just now starting on a TurboDemo tutorial.