Mercari operates an online marketplace where users can buy and sell new, like-new, and preowned items. The platform offers a wide range of products, including retro video games, organizers, workout gear, and more. Users can list items for sale and earn extra cash by selling unwanted gifts and items. Mercari also provides access to exclusive promotions and flash deals, allowing customers to save up to 70% off retail prices. The platform features top brands such as Apple, Sony, Nike, Nintendo, Funko, and LEGO.