Amazon’s Buy Box algorithm was ruled by the European Commission to be anti-competitive, persuading the technology company to reach an agreement to make third-party sellers more competitive on it's marketplace. 

EU Commissioner Margrethe Vestager had announced in November 2020 that the European Union’s antitrust unit had opened an investigation into Amazon’s criteria for sellers to feature in the Buy Box, probing concerns it artificially favoured its own retail offers and those of sellers that used its logistics and delivery services.

The European Commission preliminarily concluded that Amazon abused its dominance on the French, German and Spanish markets for the provision of online marketplace services to third-party sellers. It also preliminarily concluded that Amazon's rules and criteria for the Buy Box and Prime unduly favoured its own retail business, as well as marketplace sellers that use Amazon's logistics and delivery services. 

In response, Amazon offered several concessions to third-party sellers on its platform in Europe, including a commitment to 'apply equal treatment to all sellers when ranking their offers for the purposes of the selection of the winner of the Buy Box' and adding a second Buy Box for products that are 'sufficiently differentiated from the first one on price and/or delivery.'

The changes apply across the European Economic Area (EEA), with the exception of the Italian market, due to separate antitrust action. Regulators in Germany and the UK were also investigating Amazon’s competitive practices.

 The agreement meant Amazon avoided potetially billions of dollars in fines.