Yes, this is right. This is how the Blender makers still earn money. They sell books, tutorials, services and more.

But you need a widely accepted product to do so. A small software with 100 users will not create enough side effects like this.

I like this concept and the idea behind it but it probably is not for the small hobby user. But if you create something like Ogre3d or maybe an impressive new AI component, a better physics engine than ODE or a new innovative procedural animation system, maybe you can make a deal there.