Mercari is a Japanese e-commerce company that operates the Mercari marketplace app, which allows users to buy and sell a wide range of products. The company was founded in 2013 and has since expanded to the United States and the United Kingdom. Mercari has been successful in part due to its focus on mobile commerce and its user-friendly interface. The company has also been praised for its commitment to sustainability, including its efforts to reduce waste and promote reuse. In 2018, Mercari became the first Japanese startup to achieve a valuation of over $1 billion.