Life is surprisingly pretty good for the House of Mouse if you're a shareholder. Walt Disney (NYSE:DIS) stock hit all-time highs on Friday, and a big reason for the media giant's success is its wildly successful premium video streaming service. Disney+ checked in with 73.7 million paying subscribers when it blew out its first birthday candle last month, a jaw-dropping achievement for any premium platform.

When it launched 13 months ago its goal was to be a presence in 60 million to 90 million homes by 2024. It nailed its five-year plan in its first year. Expectations are understandably high at this point, and that could prove dangerous. Let's go over some of the reasons why growth at Disney+ should decelerate substantially at this point.

A woman looking bored as she channel surfs with her TV remote control.

Image source: Getty Images.

It's a small world after all 

We're already seeing growth slow closer to home. Disney+ may have gone from 57.5 million to 73.7 million accounts in its latest quarter, but the lion's share of that 16 million sequential gain came from India's rebranded Disney+Hotstar platform that is also now available in Indonesia. 

International growth matters, and Disney+ expanding into Latin America last month and targeting more regions for early next year will keep the subscriber count climbing. The problem here is that Disney can't charge as much as it does in the U.S. in some of the world's most populous markets. The average revenue per subscriber of $4.52 per month for the third quarter would be $5.30 a month if you back out Disney+Hotstar from the equation. 

Disney also faces a retention challenge closer to home. The media giant was aggressive in pushing discounted plans for folks willing to pay a year or more in advance before the service launched. Select Verizon Communications wireless customers received the first year of Disney+ at no additional cost. A lot of plans came up for renewal on Nov. 12. Disney's move to spring the second season of The Mandalorian on viewers just as the one-year anniversary came up is brilliant, but there will be churn that wasn't there before.

The marketplace is also changing. Some of the rival services that didn't launch with the same kind of fanfare are about to heat up. HBO Max will be getting every Warner Bros. film the same day they hit theaters through the next 13 months at no additional cost. Even the lowly Peacock service is going to turn heads next month when it becomes the exclusive home of The Office

The pandemic and -- let's face it -- the recession played starring roles in Disney's rookie streaming success. The marketplace is getting crowded, and folks just don't have enough time to stream all of the quality content coming out these days. There will be even less time once we're back to spending less time at home as we claw our way out of the COVID-19 crisis. 

Disney+ will continue to be a dominant player in this booming niche, but investors need to be realistic. Growth will slow, and perhaps markedly so, in the year ahead. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.