Monopolies and toll booths are vehicles that allow you to capture cash: in the case of monopolies, significant cash. Monopolies are created by controlling the supply of a commodity. The postal system, sports events, entertainers, and many utility companies are typically good examples. Limited competition usually means higher prices, unless there is government intervention.
Did you buy popcorn and soda the last time you went to the movie theatre? The prices are significantly higher than what you would pay at a grocery store. Once you are inside the movie theatre, they have a MONOPOLY on your business! If you want soda and popcorn while you watch the movie, you will pay their price.
A toll booth is the physical means of collecting payment for your services or product. The more effective your toll booth, the more revenue you will be able to collect from the people who do business with you. A “copyright” may give you legal rights to a product, but if customers can easily circumvent your toll booth, your revenues will be significantly reduced.
Try to create a monopoly, and try to vigorously focus as much traffic as possible through your toll booth.