Amazon says in its second-annual report that it prevented 4 billion bad listings from making it onto its site and got rid of more than 3 million phony products last year.
The results, released Wednesday, were mixed compared with 2020, when Amazon blocked 10 billion listings and got rid of 2 million phony products.
Amazon also reports it stopped more than 2.5 million attempts to create fake accounts on its third-party marketplace.
According to its report, the company implemented a program in 2021 that made it harder for fraudsters to register for accounts.
The program required those registering for seller accounts to have one-on-one conversations with an Amazon team member to verify their identity.
The program also verifies the seller's physical locations and payment instruments.
Amazon also saw a decrease in complaints of intellectual property infringement in 2021 while growing the number of active brands on its site.
Counterfeit sellers have long plagued Amazon and other e-commerce retailers, including eBay.
Amazon has stepped up efforts to fight it in recent years amid heightened scrutiny from brands and lawmakers pushing for anti-counterfeit legislation.