In viewing the repurchase cycle, both median and mean/average can represent how long all customers will come back to make another purchase. The difference is that using median can avoid being affected by some extreme situations. For example, As shown in the figure below, the average value of the repurchase cycle calculated by customer A is obviously much larger than the median because there is an interval of 1000 days between purchase of customer A, yet in reality, in most cases, customers will repurchase within a few days. In this case, using Median for the repurchase cycle would be more accurate.

＊If the number of days is even and there is no middle number, the 2 median numbers will be added up and divided, and the average value will be taken as the median number of days.

Sort the interval days of all numbers from small to large, and the median will be equal to the number of days in the middle.