The theory of computation can be used to make money in several ways. Here are some examples:

1. Software development: The theory of computation is used to design and develop software systems that are efficient and reliable. By applying the principles of automata theory, formal languages, and complexity theory, developers can create software systems that meet the needs of their clients and are profitable.

2. Artificial Intelligence: The theory of computation is used in the development of artificial intelligence systems that can perform human-like tasks such as speech recognition, image processing, and decision-making. Companies that use AI to improve their products or services can gain a competitive advantage and increase revenue.

3. Cryptography: The theory of computation is used to develop encryption algorithms that make it difficult for unauthorized individuals to access sensitive information. Cryptography is used by businesses to protect their financial information, customer data, and other confidential information.

4. Optimization: The theory of computation is used in optimization algorithms that can be used to optimize production processes, supply chain management, and other business operations. By optimizing these processes, companies can increase efficiency and profitability.

5. Computer science research: The theory of computation is the foundation of computer science research. Researchers who apply the principles of automata theory, formal languages, and complexity theory can make significant contributions to the field of computer science and earn recognition and funding.

These are just a few examples of how the theory of computation can be used to earn money. The key is to identify the specific application and use the appropriate theoretical tools to solve the problem at hand.