People tend to overestimate short-term revenue, and underestimate long-term revenue. It will probably take you much longer than you think to get 200 users, but

People tend to overestimate short-term revenue, and underestimate long-term revenue. It will probably take you much longer than you think to get 200 users, but if you stick with it and your idea is good, you'll end up with more than you ever expected.