Stacy Mitchell and Shaoul Sussman:

More than half of all internet shopping searches start on Amazon. That staggering fact has made the tech giant an all-powerful gatekeeper for every maker and retailer of consumer products looking to reach customers online. For these companies, success or failure in the pivotal online market hinges on how Amazon positions their offerings on its platform. These sellers live and die by the tech giant’s algorithms, which function as a key mechanism of Amazon’s market power.


The most consequential and fear-inducing of these algorithms is the one that controls which seller gets to occupy the “Buy Box” for a given product, the area on the right-hand side of the page that contains the eye-catching orange buttons that say “Add to Cart” or “Buy Now.” When customers click one of these buttons, they’re choosing the default seller, the seller Amazon awarded the Buy Box to. 


The Buy Box is every bit as crucial as it sounds. For any product you might shop for on Amazon – a 55-inch Samsung television, say, or the paperback edition of Brandeis on Democracy — there are often multiple sellers offering that item, including, in many cases, Amazon itself. Amazon has an algorithm that selects one of these sellers as the default seller for that product. Sellers refer to being selected as “winning the Buy Box.”


Customers can opt for a different seller, but they rarely do. That’s partly owing to the one-click convenience of those orange buttons, and also because Amazon doesn’t make it very obvious that there are other options. To select a different seller, a shopper has to locate the inconspicuous text that says “Other Sellers on Amazon” or “See All Buying Options,” and then pick from the list that appears. More than 80 percent of the time, shoppers go with Amazon’s chosen seller. If they’re using a mobile device, that rises to more than 90 percent. 


In other words, for the hundreds of thousands of companies that sell on Amazon’s platform, “winning the Buy Box” is everything.