Provided by Dow Jones By Allison Prang Amazon.com Inc. said its business-to-business segment is now generating $25 billion in sales annually, six years after its launch. Amazon Business, as the segment is called, was launched in the U.S. in 2015. Since then, it has grown to eight more countries and has more than 5 million customers. Amazon said over half of Amazon Business's annualized sales are from third-party sellers. Businesses rely on the service to buy everything from ergonomic desks to administrative tools for small businesses. Overall, Amazon Business is still a small piece of the online-shopping behemoth's total sales, which reached $386.06 billion last year. Amazon was among the companies whose sales got a lift during the Covid-19 pandemic as shoppers stayed home and relied on online ordering.