Amazon said its third-party sellers blew past $3.5 billion in sales on Prime Day, growing more from last year than Amazon's own retail business

• Third-party sellers on Amazon surpassed $3.5 billion in sales during its Prime Day event this year, a growth that Amazon said its own retail business hasn't seen.
• The news comes as Amazon remains under scrutiny following a congressional antitrust investigation, during which the company attempted to prove that it does not favor its own retail items over those of third-parties.
• Former third-party sellers told lawmakers that Amazon had listed new products onto its marketplace through its own private-label that looked nearly identical to their own.
• The House said evidence shows that the ecommerce giant indeed uses third-party data to copy popular third-party products, thereby pushing them out of business.

Amazon said third-party sellers on its online marketplace raked in $3.5 billion in sales during this year's Prime Day, a 60% rise from last year. According to the company, that growth is more than its own retail business has seen.

Third-party sellers play a large role in Amazon's online ecosystem and are made up of mostly small and medium-sized businesses. The company said in a press release published Thursday that its 2020 Prime Day "delivered the two biggest days ever for third-party sellers."

"Amazon is on track to invest $18 billion this year to help small and medium-sized businesses succeed in its store, and designed this Prime Day to support small businesses even more—including funding a promotion that helped drive over $900 million in sales for small businesses in the two weeks leading up to Prime Day," the company said in the press release.

An Amazon spokesperson confirmed to Business Insider that this year's Prime Day was the company's biggest sales day ever, a designation noticeably missing from the press release. During 2019's Prime Day event, the company said it raked in more sales than its 2018 Black Friday and Cyber Monday promotions combined.

Amazon's 2020 Prime Day comes as the company and its big tech peers remain under scrutiny following a congressional investigation over antitrust concerns. Amazon specifically was in the spotlight over its treatment of third-party sellers. Some former sellers told lawmakers that the company has released new products through its private-label that appear almost identical to theirs. The House concluded that Amazon uses third-party seller data to copy the most popular products listed on the online marketplace, according to a report detailing lawmakers' findings.

The investigation isn't the first time that Amazon has been accused of scraping third-party data. Employees spoke out in 2019 regarding how easily Amazon can access sellers' data and share it with its retail team.

The annual Prime Day event is typically held in July but was delayed to mid-October in light of the COVID-19 pandemic. According to a new filing by an Amazon employee — who is already suing the company over poor work conditions — Amazon, in an effort to expedite operations during Prime Day, reinstated a policy allowing managers to discipline employees who take time to wash their hands and sanitize.