Best-seller rank

Best-seller rank is where a product sits in a store's own sales order. Many store platforms let shoppers sort a collection by "best selling", and Shopify stores in particular expose this sort order on their collection pages. The product in first place is the store's top seller over the period the platform uses for that sort.

The rank is relative to one store. Rank 1 on a small store may sell fewer units than rank 20 on a large one. That is why RivalSonar combines rank with the store's estimated orders. A store's estimated orders are split across its best sellers with a power curve, so the top product takes the biggest share and each lower rank takes less.

Useful ways to read it:

• Movement matters. A product that climbs from rank 15 to rank 2 in a week is more interesting than one that has sat at rank 1 for a year.
• New products near the top suggest the store found something that works quickly.
• Compare across stores. If the same product ranks high in several stores, demand is broad.

The guide on how to find a store's best sellers shows how to read rank by hand.