This greatly depends on your experience level, how much work you put in every day, the type of business you are in, you're personal situation, and quite a few o

This greatly depends on your experience level, how much work you put in every day, the type of business you are in, you're personal situation, and quite a few other factors. If you're at the top of your game (you know what you are doing - have experience of 5-10+ years), I would say if the income does not come in after 3-6 months, you're wasting time and effort. Otherwise it could take years to get things right before you find out that the market for your idea is not there.