My advice would be to find a publicly-traded company that operates one of these small businesses on a larger scale. You can then go to the investor section of the webpage and find their most recent annual financial statements (you are looking for their 10-K, which is filed with the SEC). Once you find their financial statements, you can look in their income statement at their gross margin percentage. Using this as a baseline, you can subtract a few percentage points due to their economies of scale. Once you get your GM percentage, then you can factor in the average annual rent rates, cost of employees, etc. for your area to arrive at what you think your net income percentage would be for the year. This is a starting point and can at least get you close to the information you are looking for.
To answer your question off the cuff, I would say a local dry cleaners makes between $60k to $80k per year, depending on volume and how it is run. Laundromats are less than that because more and more people have washers and dryers in their homes now. For a laundromat, location is king because if it is in a college area or an area where most people do not have their own washer/dryer, that location will obviously make more!
I think it is very difficult to answer your question because there are so many different variables in business. I am sure for every one coffee shot or dry cleaners that makes money, there are probably 5 who don`t.