Here's a for-instance:

I gave her an assignment to buy an adult magazines with stories in it. She's never done that, and was more than a little nervous. She came through with blazing colors, and to boot, she enjoys the stories very much. When she got home, she couldn't wait for her next assignment.

Once when we were doing the cell-phone vibrations, right when she was coming, I told her not to remove it, and kept calling. She came again almost immediately, and was "OMG"-ing over and over. I loved the control I had, and the effect it had on her.