Year-over-year (YOY) is a comparison of a company’s performance or financial results from one year to the same period in the previous year. This is considered an important metric for determining growth, as it offers insight into how much improvement has been achieved over the course of the entire calendar year. Year-over-year analysis also allows companies to analyze trends, as well as spot opportunities and areas of concern. Whether tracking sales numbers, customer acquisition rates, or profit margins, YOY can be a powerful tool for understanding performance and for making informed and strategic decisions about the future direction of a business.