In the most recent UK collective lawsuit filed by the merchants, they are seeking financial reparation for the company’s purported past behaviors. Boris Bronfentrinker, a partner at Willkie Farr & Gallagher law firm and legal advisor to the claimants, asserts, “The most evident and primary consequence is a decline in revenue and profits. Amazon is diverting sales from sellers by utilizing competitor data to introduce its own products to the market.” He further adds, “When companies gain market dominance, they must act responsibly. They do not have unfettered freedom to act as they wish.”

Despite the multiple ongoing investigations and accusations following a similar narrative, the merchants are encountering obstacles. Bronfentrinker argues that the case is solid because the undertakings made to the EC and CMA essentially imply an admission by Amazon of violating competition laws: “Their own acknowledgment that they will cease such practices is a clear indication of guilt,” he remarks. Nonetheless, in practical terms, according to Kathryn McMahon, an associate professor of law at the University of Warwick, the merchants will need to compile a new case since there is no formal record of Amazon breaching any laws as of now. “Entering into the commitments does not equate to an admission of guilt,” she remarks.

Hence, the merchants must first establish Amazon’s market dominance in the UK, a notion likely to be contested by the company, as per McMahon. Subsequently, they need to prove that Amazon misused its dominant position to harm the sellers on its platform. “That’s where the challenge lies,” McMahon remarks.

The argument that Amazon exploited its dominance is grounded on a relatively unexamined concept in competition law: self-preferencing. This concept posits that major digital platforms should not misuse their advantage in a specific market, for instance, e-commerce, to promote other sectors of their business at the expense of potential rivals. In 2017, the EU discovered Google in breach of antitrust laws due to self-preferencing—specifically favoring its shopping services using its dominance in the advertising industry. Recently, the UK implemented new regulations to curtail the damage caused by self-preferencing. However, there is limited precedent on which the claimants in the Amazon case can build their case. Niamh Dunne, associate professor of law at the London School of Economics, remarks, “Self-preferencing has gained significance as a harm concept only in the last decade. It remains an evolving area.”

Given the scarcity of legal precedents, the case will rely to some extent on the distinction between a sensible business strategy and anti-competitive self-preferencing. It is not inherently illegal for Amazon to operate an online marketplace, sell its own products through it, and handle logistics, even though this may confer it a competitive edge. “One of the challenges with self-preferencing is that integrated firms commonly engage in it. While it may have adverse effects on competitors, it’s a common practice,” Dunne comments. She suggests that Amazon could argue that it has been merely following “the law of the jungle.”

Before these arguments can unfold, the merchants’ lawsuit must receive certification from the UK’s Competition Appeal Tribunal, which is not expected to reach a decision on the case’s viability until early next year.

The merchants are willing to await their day in court. “Should this class action reinforce the changes proposed by the European Commission and CMA, and if companies like Amazon realize they cannot mistreat their partners, then we will have accomplished something,” Goodacre states. “Amazon is quite a voracious entity. I say this with an envious respect. However, it comes at a price for someone.”