just to add - you've to work the marketing problem from reverse. how much money do you want to make - have an absolute cap on the annual amount e.g in 5 years

just to add - you've to work the marketing problem from reverse. how much money do you want to make - have an absolute cap on the annual amount e.g in 5 years you want to make 2m|5m|10m a year. then choose your markets based on whether they can support that amount.