Purchase Frequency is the number of times that a customer makes a purchase in a given period of time. In research, understanding how often a consumer purchases within a given category gives a sense of their engagement. For example, the question asked is often in the form of "how often do you purchase _____?" The response list is set based on how often people typically purchase the category. For a product that is purchased often such as mints or gum, the list may start with "Once a day or more often", followed by increasing time frames (e.g. once every two to three days, once every 3-5 days, etc.). For products that are not purchased as frequently, particularly those outside of CPG, the time frames are more commonly measured from months to years. Purchase frequency is related to purchase cycle (see related definition) and can be used to estimate repeat purchases in sales forecasting.