Why not sit down with them at a computer and show them the actual site?
Not sure if you're a cam girl, clip maker, or what sites you're on, but I know it's often difficult to explain to friends just what I do on MFC. By showing them the actual cam site itself, it starts to paint a much clearer picture of what camming is like: the different styles of camming, the models themselves, room atomosphere, the responsibilities that come with it, etc.