To determine if earning $100 in profit per month while working 12 hours a day is realistic, we need to consider various factors such as the type of work, industry, location, and individual circumstances. While it is challenging to provide specific examples and references without knowing the specific job or industry, we can discuss some general considerations.

1. Type of work: Different types of work have varying profit potential. For example, if you are engaged in freelance writing or graphic design, where you can charge clients per project or hour, earning $100 per month might be more realistic compared to jobs that pay hourly wages.

2. Industry and location: The industry you are working in and the location can significantly impact your earning potential. For instance, earning $100 per month might be feasible in some developing countries, where the cost of living is lower, but it might be very difficult in developed countries with higher living expenses.

3. Hourly rate: To assess the feasibility of earning $100 in profit per month, you need to determine your hourly rate. If you are earning an hourly wage, you can calculate the number of hours you need to work to earn $100. For example, if you earn $5 per hour, you would need to work 20 hours per month to reach $100 in profit.

4. Expenses and taxes: Consider your expenses, including transportation, equipment, supplies, and taxes. These costs can significantly impact your monthly profit. If your expenses are high, it might be more challenging to achieve $100 in profit.

5. Other commitments: Working 12 hours a day leaves little time for other activities, which might limit your ability to take on additional work or side projects that could increase your profit.

It is important to note that the information provided here is general, and the specific circumstances of the individual can significantly impact their earning potential. It is advisable to research the specific industry, location, and job market to get a more accurate understanding of the earning potential.

Additionally, seeking advice from professionals in the specific field or industry can provide valuable insights and references to determine the realistic profit potential.