It is very important to analyse your markets whether you are starting a business or you are in business already. Existing businesses continuously work on budgets/sales forecasts which should generally be influenced by the prevailing behavior of the market among other factors. You cannot derive your forecasts purely on targets you want to achieve, you have to check your targets against the reality of the market situation.
Considering the info about your markets is not an excuse for you not to achieve sales forecasts, however, it is a way to ensure that you can marry the right strategy to achieving your targets by using marketing analogies to derive your strategies.
A good market analysis must consider the following;
1. Who are the purchasers of your products - geographic, demographic etc? Why do they buy from you or why would they buy from you? is it the quality of your products? or the price? etc
2. What is the size of the market? Is it growing or shrinking? Is it profitable?
3. Consider your market share or if you are a new business, what market share are you targeting over what length of time?
4. What is the industry outlook?
With this kind of analogy you will be able to develop the right marketing plan/strategies to compete and achieve your targets.