MAC is the middle-ground approach in the industry as it averages the price on a rolling basis. We use MAC over the other two methods because, the Last-In, First-Out (LIFO) method assumes that the last unit to arrive in inventory or more recent is sold first and The First-In, First-Out (FIFO) method assumes that the oldest unit of inventory is sold first.
The biggest advantage of using MAC is that it's easy to use in QuickBooks Commerce and track inventory expenses compared to the aforementioned methods. Another key takeaway is that once you have taken units out of your inventory, you do not need to track their original costs before pricing them again (i.e. auto-calculated).