In Shopify, the items are considered bestsellers based on the number of times they were ordered, but the quantities sold are not taken into account. So, for example, a t-shirt A ordered as a single item 5 times will have more relevance than a t-shirt B that has been sold 3 times in quantities by 2 i.e. t-shirt A with 5 items sold will have a higher rank than t-shirt B with 6 items sold. Our app tracks quantities sold and sale totals which allows more advanced and flexible bestseller collections.