Jeff Bezos speaks onstage at WIRED25 Summit: WIRED Celebrates 25th Anniversary With Tech Icons Of The Past & Future on October 15, 2018 in San Francisco, California.

Amazon's hunt for another business to drive growth even higher may have its answer in Amazon Business, a note from Bank of America on Tuesday said.

Amazon Business represents Jeff Bezos' company expanding into the market of business-to-business (B2B) e-commerce. The Amazon unit was re-branded from "Amazon Supply" seven years ago. Amazon Business "combines positive attributes of Amazon's consumer marketplace," such as broad selection and delivery convenience with the products and benefits that are "tailored for businesses, government organizations and the education sector," Bank of America analyst Justin Post said.

"B2B has many more hurdles to adoption given the complex (and often offline) procurement processes, but Amazon is driving steady adoption," Post said

While Amazon Business is just beginning to establish itself, Bank of America projects there is a total addressable market for e-commerce B2B of $1.4 trillion by 2021, which is nearly double the firm's estimated $761 billion market for consumer e-commerce. Essentially, the market potential for Amazon Business is about twice the potential for its core retail business.

Amazon Business may have a long way to go to catch the retail unit but it's growing fast. Post said it now has "millions of business customers." He pointed to growth of the run rate of gross merchandise volume for Amazon Business (its estimated gross sales extrapolated out on an annual basis). In the past two years, that run rate has increased by 10 times: From $1 billion in 2016 to $10 billion in 2018, Bank of America said. And by 2023, the firm estimates Amazon Business can scale that gross merchandise volume run rate to $33.7 billion, with $16.1 billion in revenue.

Bank of America also believes that it's realistic to expect that by 2021 Amazon Business will capture 10 percent of the B2B market in the U.S. and 5 percent of the international B2B market. At that market reach, Bank of America said the unit would generate between $125 billion and $245 billion of added value for Amazon as a whole.

"The company is solving procurement bottlenecks with new features, and we think Amazon is well positioned in the category with an active marketplace and same-day fulfilment capabilities. Long-term, B2B will be an important driver of retail sales growth," Post said.

"Recently introduced Business Prime increases the value of the offering with features like faster delivery, account management, spend analytics, and integration with existing procurement applications," Post added.

Amazon closed trading Tuesday up 1.1 percent at $1,761.85 a share. The stock has risen more than 17 percent this year.

WATCH: Jeff Bezos is so much bigger than Amazon — a look at his extraordinary empire