Amazon Buy Box

Buy Box is a feature Amazon displays on its website product pages to encourage shoppers to add a particular seller’s item to their cart. It is located on the right-hand side of the listing and includes the price, shipping details, seller and fulfillment method, and “Add to Cart” and “Buy Now” buttons.

Between 82 to 90 percent of Amazon shoppers are estimated to use the Buy Box when purchasing products on Amazon. For a seller to be eligible for the Buy Box, they must have a Professional Seller Account. Amazon’s algorithm determines which seller’s offer appears in the Buy Box based on various factors such as price, shipping options, seller performance metrics, and inventory availability. 

According to Amazon, sellers with competitive prices, high seller ratings, and fast shipping times are more likely to win the Buy Box for a particular product. In 2007, Amazon founder and then CEO Jeff Bezos argued that the company used 'very objective customer-centered algorithms' to automatically award the Buy Box to the lowest priced seller, provided they had the item in stock and were able to deliver it. 

Amazon does not reveal the specifics of its Buy Box system, though it is considered highly probable that machine learning plays a significant role, given the complexity of the decision-making process, the need to adapt to changing market conditions, and the large amount of data involved.

Risks and harms 🛑

Amazon Buy Box has been criticised for potential anti-competitive practices and violation of consumer protection law, as well as poor ethics and inadequate transparency and accountability.

Transparency and accountability 🙈

Amazon's Buy Box algorithm is seen to suffer from a number of important transparency and accountability limitations:

• Black box system. Amazon keeps the precise workings of its Buy Box algorithm confidential, treating it as a trade secret and making regulatory scrutiny challenging.

• Inadequate consumer information. Amazon provides only general guidelines about factors that influence Buy Box placement, without detailed explanations or weightings. Shoppers are given no information on how the Buy Box selection impacts their purchasing options and decisions.

• Lack of external auditing. No comprehensive third-party audits of the Buy Box algorithm have been conducted or published.

• Limited seller recourse. Sellers are highly dependent on Buy Box placement for sales, but have limited recourse if they feel unfairly treated by the algorithm.

Legal, regulatory 👩🏼‍⚖️

• European Commission (2022). Commission accepts commitments by Amazon barring it from using marketplace seller data, and ensuring equal access to Buy Box and Prime

• European Commission (2022). Antitrust: Commission seeks feedback on commitments offered by Amazon concerning marketplace seller data and access to Buy Box and Prime

• UK Competition and Markets Authority (2022). CMA investigates Amazon over suspected anti-competitive practices

• Autorità Garante della Concorrenza e del Mercato (2021). Sanzione di oltre 1 miliardo e 128 milioni di euro ad Amazon per abuso di posizione dominant | Report (pdf)

• European Commission (2020). Antitrust: Commission sends Statement of Objections to Amazon for the use of non-public independent seller data and opens second investigation into its e-commerce business practices | Amazon Buy Box case register

• European Commission (2018). Margrethe Vestager announces preliminary investigation into Amazon use of merchant data

Research, advocacy 🧮

• Gomes-Losada A., Duch N. (2019). Competing for Amazon’s Buy Box: A Machine-Learning Approach

• Chen L., Mislove A., Wilson C. (2016). An Empirical Analysis of Algorithmic Pricing on Amazon Marketplace (pdf)

Investigations, assessments, audits 🧐

• Institute for Self-Reliance (2021). Amazon's Toll Road

• ProPublica (2016). Amazon Says It Puts Customers First. But Its Pricing Algorithm Doesn’t

News, commentary, analysis 🗞️

• https://themarkup.org/amazons-advantage/2021/10/14/when-amazon-takes-the-buy-box-it-doesnt-give-it-up