Amazon FBA: The Best Products To Sell On Amazon FBA Rule #1: Amazon Best Seller Rank. So the best selling rank of your potential product needs to be between 300 and 5,000. The BSR refers to the product's top-level group. You should see items that will have both a sub-level style, and a top-level style, so it's important to only look at the BSR range of an item's top-level style.