The coronavirus pandemic has spawned a massive acceleration in the shift toward online shopping. And while state economies are beginning to reopen across the country, it’s unlikely that shoppers will completely abandon their newfound online shopping routines to return to brick-and-mortar stores.

And none other than Amazon (AMZN), saw significant gains as a result of coronavirus-related lockdowns. According to Mark Mahaney at RBC Capital Markets, Amazon’s performance during the novel coronavirus quarantines has made it the “best global play off of online retail.”

But while users have clearly been spending more time shopping on the e-commerce giant’s site, the sudden surge of new customers brought on by the virus has put a hurting on one of the company’s key metrics: customer satisfaction. And if left unaddressed, that could seriously hurt the company’s growth moving forward, Mahahey said.

Users are shopping online more than ever

According to RBC’s 8th annual U.S. Online Shopping Survey, online shopping accelerated from January through April, with the last month seeing a 22% year-over-year increase in ecommerce. It wasn’t just Amazon that benefited from the shift, though. Walmart (WMT), eBay (EBAY), and Etsy (ETSY) also saw a boost from the shift to online shopping brought on by the pandemic.

But according to Mahaney, that boost is unlikely to fall off must when physical stores reopen, as the move has created a sustainable shift in consumer behavior.

“We asked our survey respondents who had shopped online, if they believed the COVID-19 crisis will lead them to permanently increase their willingness to purchase Online vs. in-store and a majority (54%) of them said...Yes,” Mahaney wrote.

Proof of that comes in the increase in Amazon’s Prime customers. The service, which costs $119 a year, grew from 59% penetration in 2019 to 67% in 2020. That’s got Amazon on pace to hit 200 million Prime subscribers worldwide, up from 150 million in January.

Prime users are key for Amazon’s e-commerce arm because they provide a continuous stream of revenue for the company versus the revenue generated by one-off purchases by consumers.

What’s more, Amazon customers are also making larger purchases. According to RBC’s study, 64% of respondents said they made at least 2 to 3 purchases via Amazon per month in 2020. That’s up from 54% in 2019. On top of that, customers are spending more on the site than last year, with 45% of respondents saying they spent more than $200 this year versus 36% in 2019.

Customer satisfaction is falling

Despite the spike in sales and Prime subscriptions, Mahaney says RBC’s survey found that customer satisfaction with Amazon has hit an all-time low.