Amazon’s e-commerce empire is rapidly expanding, driven in part by its subscription-based Prime service. One analyst predicted the service, which costs $119 per year, will draw in nearly 300 million customers by the end of the next decade, according to CNBC.

Citigroup analyst Mark May addressed the growth of Amazon Prime in a Sunday note. Prime tallied 101 million subscribers at the end of last year, but May said that number could significantly rise over the course of the next decade.

By 2029, there could be more than 275 million Amazon Prime subscribers, according to the note. That would represent a 172 percent increase over a little more than 10 years.

May’s note pointed out that Amazon has increased Prime membership numbers by 35 to 40 percent per year. If Citigroup’s prediction comes to pass, 80 percent of homes in the United States could subscribe to the all-encompassing service, per CNBC.

GettyImages-646731478 Amazon Prime could have 275 million members by 2029. An Amazon prime video logo it's displayed on a Sony Xperia Z5 premium during the Mobile World Congress on the third day of the MWC in Barcelona, on March 1, 2017. Photo: Josep Lago/AFP/Getty Images

Amazon has made Prime an enticing deal by offering benefits in a number of different service sectors, so much so that customers may feel like they are missing out by not subscribing to the service. For starters, Prime members get free and expedited delivery on a number of products sold on the company’s flagship digital storefront. Citigroup’s analysis found that Prime members spend twice as much money on Amazon as those who do not subscribe to Prime.

Outside of discounted shipping on delivered goods, Prime has conferred a number of new benefits throughout 2018. Prime members can now get savings at Whole Foods Market organic grocery stores, as of June. Some Whole Foods stores even offer curbside delivery for Prime members. Amazon bought the specialized grocery chain in 2017.

Also in June, Amazon started letting Prime members sample clothes they bought online for a week before deciding if they want to keep them. If Amazon follows through on buying the Landmark movie theater chain, Prime members may even get benefits at the movies, too. The service already grants access to a large audio and video streaming library.

Amazon recently became the second U.S. company to exceed $1 trillion in market value, after Apple. The company has been roundly criticized by some, including Sen. Bernie Sanders of Vermont, for its growth at the expense of overworked and underpaid warehouse employees.