This question is very broad so it's tough to answer, but I'll give it a shot.

Is there anyone else making money in that market? If so, how? What business models are working well?

Take the automobile industry. There are hundreds of business and revenue models in the auto industry (wholesale, retail, repair, parts, leasing, specialization, etc.)

There is potential profit in every market, it's the intersection of the market and your particular business model or product / service that determines the profit.

If you can be more specific, I can give you a better answer.