Prime subscribers are known to be more lucrative to Amazon, estimated to spend twice as much money every year than non-members, according to Consumer Intelligence Research Partners.
In 2014, Amazon spent $1.4 million with The Post, with no payment to Amazon disclosed.
The company hasn't previously offered a specific number about its Prime members, instead keeping the size of one of its most important businesses a secret until now.
A recent survey from Loop Capital Markets indicated that 23% of Prime members would definitely cancel their membership if streaming were not included.More news: Real Madrid's Sergio Ramos could be banned for Champions League semi-final
"It would make ideal sense to us that there would be over 100 million global members, based not only on that number but everything we've seen since then", Levin said.
Additional details about Prime are likely on the way next week - Amazon is scheduled to announce quarterly earnings on April 26.
The marketplace is an important business because it vastly expands Amazon's inventory and it's generally more profitable than its direct sales, since Amazon doesn't purchase the items itself. The company's own goods are also selling well, according to Bezos, who says previous year was the best yet for Amazon Hardware sales, like Echo and Fire devices.