Make sure you have enough money to survive for 6 months min. for space, utilities, and any other operational costs.
Income in area
Enough money to market in the area-low cost marketing is not always ideal
Your passion and willingness to be a business person more than your passion for the class you teach. You need to do what is best for the business over what you thought may work.
I have constantly changed to make things work and offered different products and services. Be adaptable
Your markets Disposable Income
LOCATION, LOCATION, LOCATION
Marketing Diversification (cross mrktng. ops avail?)
*what distinguishes your service from the rest and promote this. You want to retain business @ all levels. This is one of the simplest controllable factors that keeps me in front of people, new & long term friends/clients.
Most definitely, your overhead. Can the prices your propose, and the participation that you project, support your overhead. A very important threshold issue/question to consider.
Rent presumably, and other expenses, will be on the high side in Cambridge, but you have population density on your side. I agree with Harris that aspects of access are very important (mass transit, parking, safety, etc). And yes, absolutely, a review of your competition is helpful. Make sure to look at other stand alone studios, as well as health clubs. And if you are in a student heavy area remember to see what other options are available for them. See if you can get some data on residential/business in your area. A residential area that has a high median income will have more possibilities for mid morning classes, while an area with lots of businesses might make lunch classes a draw.
Do you already have a following in the area on which to build? The most successful Pilates/barre studio I know was started by two women, one of whom was one of the most popular teachers in the area already, and had the following in a demographic that had plenty of money and a readiness to follow her to a space where they would pay more for her class. Even if the demographics are all right having a ready base is really helpful when you move out into your own space.
Find out what times people would want to work out, if most people work they may want a 5:30 am class
Is there a demand for a studio?
Can you rent out a space as an independent contractor and build your base that way?
Once you get a following you can then open your own studio
Studio ownership is very challenging!