Not all businesses are destined for glory. There needs to be a high demand for the products you're selling, otherwise you'll struggle for years and end up failing to reach success. It's incredibly important to know if the market still needs suppliers
I run a private 20M manufacturing co. by day and trade by night. This requires a lot of DD on my part because I can't trade at a moments notice. I look for good companies that are down on their luck and where I agree with their recovery plan.