Get your mind out of the gutter. There's nothing illegal going on here because there are several ways that you can cash in on your body. Obvious places to start would be modeling or acting. Art models, for example, can make between $20 to $25 per hour. However, you can also participate in medical studies or sell everything from plasma, sperm, breast milk, and even donating eggs for approximately $5,000.
The ego is the driver making the decisions. It decides between the devil (the id) and the angel (the super-ego) on either shoulder (yes, all those cartoons you've ever seen are partly true). We have voices in our mind, and it's up to the ego to decide which one to fulfill. Its goal is to satisfy the id in some way while also attending to the super-ego.