You'd also need to consider the demographics of where your thinking of setting up. How many are "blue collar", so to speak, and are more likely to try and do the work themselves? How many are likely to hire out? What are the properties like - larger lots with lots of trees, hedges, shrubs or smaller lots with huge houses and the token Japanese Maple in the front yard.
We're in BC and find that there are definately areas where we know a quote is almost always a waste of time, then there are those neighbourhoods you can spend a month working in.
Doing your research is huge. Also, a lot of the more established companies don't advertise anymore but get a large amount of the work around. I'm not sure how you would find out if there are any like that around but it's good to know otherwise you're not really sure how many companies are out there you are competing against.
Best of luck!