A person should always have multiple options, backup plans, and alternative resources available, as relying solely on one thing can result in inescapable difficulty should it fail or be taken away. I just think it's risky building an entire business off one product. What happens if starts to fail on the market. The mouse that has but one hole is quickly taken, after all. The best advice I can give is to diversify your sources of revenue, because the mouse that has but one hole is quickly taken.