E-commerce giant Amazon provided two key updated figures about its B2B supply segment — Amazon Business — on Tuesday, illustrating the unit's remarkable growth since its launch in April 2015.

Amazon Business shared that it has surpassed 1 million business customers since its launch. That figure has more than tripled in size from May 2016, when the unit reported that more than 300,000 purchases were made on Amazon Business in its first year as it topped $1 billion in sales.

Amazon Business also shared that it now has more than 85,000 business sellers, dwarfing the 30,000 sellers it had in its first year and nearly double the 45,000 amount it reported this past January, at which time it also stated it had more than 400,000 sellers.

Prentis Wilson
Amazon Business Vice President

"We are grateful to our customers for helping us reach this significant milestone," said Amazon Business vice president Prentis Wilson in Tuesday's press release. "Their feedback has been invaluable in helping us better serve businesses and organizations of various sizes — from local government agencies to global enterprises, we are constantly looking for ways to innovate on behalf of customers, and will continue to build out features that delight them. We are striving to set a new standard for B2B e-commerce with Amazon Business, and it's still day one for us."

The company didn't provide an update on the sales growth for Amazon Business. When it last provided an update in May 2016, Wilson said Amazon Business was growing sales at a rate of 20 percent each month and offered more than 9 million products, ranging from MRO supplies to paperclips. Back in 2012, Amazon Supply offered only 500,000 products.

So far, Amazon Business is only available in the U.S., U.K., Germany and India.

Amazon shared customer testimonial quotes and examples from Siemens, King County (home of Amazon's headquarters in Seattle), and Stanford University that aimed to exemplify the ease of using Amazon Business.

"Amazon Business is taking a lot of weight off of our shoulders," said Drake Paben, Siemens Corp. director of IT procurement. "Depending on the type of business, our teams may need tools delivered in a matter of hours, large amounts of office supplies, or big pieces of machinery for our factories. With Amazon Business, we're able to automate a lot of orders and give our employees, divisions and factories the products they need to complete their jobs in a timely manner. They can find products easily on Amazon Business, and get them delivered in a very short amount of time. We are looking forward to expanding our procurement capabilities with Amazon Business."

Amazon Business' rapid growth suggests that it could serve as the 'fourth pillar' that Amazon has been driving for to complement its e-commerce marketplace, Amazon Prime and Amazon Web Services.