To do this, the forecasting model must take into account such things as product awareness, distribution, price, fulfilling unmet needs and competitive alternatives.
where, Multivariate techniques such as regression can be used to determine the values of p, q and N if historical sales data is available.
The Fourt-Woodlock model is another method used to estimate product sales.
The left-hand-side of the equation is the volume of purchases per unit time (usually taken to be one year).
HH is the total number of households in the geographic area of projection, and TR ("trial rate") is the percentage of those households which will purchase the product for the first time in a given time period.
MR is "measured repeat," or the percentage of those who tried the product who will purchase it at least one more time within the first year of the product's launch.