dress store in a downtown shopping mall. The shopping mall manager says that womens clothing stores in the mall average between $200 per foot and $250 per foot per year.     After checking with other clothing retailers, reading trade magazines, visiting similar stores in other cities and integrating her own experience in the business, Antoinette decides that she can achieve the $250 per foot per year figure. This means her annual sales should be $500,000 (2,000 x $250). To be conservative, she plans for the first years sales to be about 20% below that level to allow for her business to build. This means that first-year sales will be about $400,000, or $200 per foot.     Because Antoinette must forecast monthly sales for the first two years, she now has to decide how the sales revenue will occur each month. She could simply divide this $400,000 by twelve months and get $33,333 per month. But in the dress business, Antoinette knows, this would be inaccurate. In womens clothing, there are four sales seasons: spring, early summer, fall and Christmas. The kind of shop Antoinette plans to open is slow in mid-summer and in January and February. Antoinette also figures that sales will be a little lower than the average for the first few months until her advertising campaign catches on.     Antoinettes monthly sales add up to $401,000 for the first year, so she reduces the December figure by $1,000 to make a nice, round $400,000.       Some chain stores, such as supermarkets and drug stores, have refined the art of estimating sales to a science. Of course, they have the advantage of learning from their experience with their other stores. Even so, they occasionally make bad estimates.     Supermarket executives first gather statistics on how much the average person living in town spends every week in grocery stores. These numbers are available by obtaining total sales volume of grocery stores from the state sales tax agency; normally that data is broken down by county. They estimate how many people live in the area for which sales volume statistics are gathered. Dividing the sales volume data by the number of people in the area gives them the average sales per person from grocery stores.     Then they compare the average sales per person with state averages. If its higher, it might mean that people living in the area have a higher-than-average income. They can verify that by referring to the United States Census, which lists average income per family and per person for every census tract. If the income per person is average or below average, and sales per person are higher than average, it probably means that people come from surrounding areas to do their shopping. If the sales per person are lower than average in the area, it might mean that income is below average or that people leave the area to do their shopping. On the basis of this sort of data, together with an analysis of competition and demographics, supermarket executives can develop relatively accurate estimates of sales volume for a new store.     b. Service Business Sales Revenue Forecast     To estimate sales revenue for a service business, youll need a good understanding of what steps you go through to generate a billable sale. Then make a forecast of how many times you expect to go through all those steps every week or month and how much revenue youll derive from those steps.