Physical volume of product sold at retail expressed in packages. This is the unit that the shopper buys in the store. Use when comparing products of the same size. Most often used by Operations, also in pricing analyses. Also, in some databases, used as a substitute for a volume when no volume measure (e.g. pounds, tons, liters) is provided.
Reference article: Ways to Measure Sales
A vital distinction. While revenue tracks the health of the business, unit sales track the velocity of the product. For anyone focused on operational efficiency or inventory management, units are the ‘ground truth’ that reveals exactly how a product is performing in the real world, stripped of the noise of fluctuating pricing or discounting.