A new report has accused Amazon of exploiting a ‘captive clientele’, with data showing substantial increases in the fees sellers must pay to use the platform.

Amazon has been strongly criticised by researchers from the Amsterdam-based Centre for Research on Multinational Corporations, also known as Somo, following the publication of a report that exposes how much the online retailer has ramped up sellers fees and advertising costs.

The report found that between 2017 and 2022, Amazon had tripled the amount it earned from fees for independent sellers in Europe, including for listings, deliveries and digital support. Income from sellers’ fees jumped 6% last year to €23.5b, even as retail sales fell 1%, according to Somo’s analysis of accounts for the group’s European arm, Amazon EU Sarl. That growth far outstripped the rise in sales, which doubled over the same period.

According to The Guardian’s Sarah Butler, those fees do not include the amount sellers are charged to advertise on the site. Amazon’s overall advertising revenue has boomed in recent years: to €5.4b in 2021 from just €0.3b in 2017, according to Somo’s analysis of local Amazon subsidiaries that book its ad services across Europe. The group estimates that 51% of that amount, or €2.75b, comes from independent sellers.

Margarida Silva, a researcher at Somo, said: “For the past 20 years Amazon has been expanding its monopolistic hold over online shopping in Europe. It is now so dominant that independent retailers who wish to sell online cannot avoid it. Sellers are locked in to the platform and essentially a captive clientele, making them a profitable source of monopoly rent.”

The report states: “Amazon sellers seem to be increasingly shouldering Amazon’s costs, including the costs of the expansion of its network of fulfilment centres and also the digital services taxes in France and the UK. Amazon’s squeezing of sellers is a crucial pillar of its European business as revenue from independent sellers’ fees is growing faster than its core business, its European retail arm.”

Amazon has responded to the report by saying it ‘strongly disagrees’ with its characterisation as monopolistic. In a statement, the ecommerce giant said the figures within the report ‘fundamentally misrepresent how the retail industry works’, and pointed out that “sellers have many options to choose where to sell goods”.