Cord-cutters looking to subscribe to HBO won't need an Apple (NASDAQ:AAPL) product after all.

Dish Network's (NASDAQ:DISH) new Internet-based TV service, SlingTV, has added Time Warner's (NYSE:TWX) premium network to its line-up. Now, SlingTV subscribers can get access to HBO's programming without a traditional cable subscription.

Although it's a bit different than Apple's exclusive service, HBO Now, it certainly lessens the appeal of Apple's offering.

Apple's "exclusive" HBO deal
HBO's CEO, Richard Plepler, announced HBO Now at Apple's Spring Forward event back in March. HBO Now, like HBO Go, offers access to HBO's content streamed over the Internet. HBO Go, however, requires a cable subscription. HBO Now, in contrast, is open to anyone.

For the first three months, Apple will be the exclusive digital provider of HBO Now -- those who want to access it will need an iPhone, iPad, or Apple TV. This gives Apple's hardware -- particularly the Apple TV -- an obvious (albeit temporary) advantage over its competition.

Apple TV has not been significantly upgraded in over three years, and though it's perfectly capable of streaming HD content, significant competition has emerged. The cheaper $35 Chromecast has overtaken Apple TV in terms of market share, and competing products such as the FireTV, Nexus Player, and Roku 3 now offer better capabilities, including voice search and support for an app store.

But cord-cutters (or would-be cord-cutters) looking to subscribe to HBO Now could be enticed to purchase the Apple TV over its cheaper or technologically superior rivals. They may be better products, but they can't offer the latest episode of "Game of Thrones."

Sling TV is available for a wide variety of devices
Dish's new service could change that. Launched in February, Sling TV is a $20 per month Internet-based streaming service that gives subscribers access to about a dozen channels, including the sports stalwarts ESPN, TBS, and TNT.

Now, for an additional $15 per month, Sling TV subscribers can bolster that base package with HBO -- both the live channel and a wide array of on-demand programming. Sling TV isn't available on Apple TV, but it is accessible on many set-top boxes and game consoles, including Roku devices, FireTV, and Xbox One. SlingTV, augmented with HBO, allows cord-cutters a way to watch "Game of Thrones" without an Apple product.

HBO Now is unbundled
Still, there's one major limitation to Dish Network's offering: It requires a basic Sling TV subscription. A cord-cutter who wants HBO but has no interest in Sling TV's other offerings would wind up paying an additional $20 per month compared to just the basic HBO Now package. In that instance, Apple's offering remains superior -- Sling TV's inclusion of HBO begins to resemble the expensive cable bundles many detest.

Apple's exclusive offering of HBO Now still gives it an advantage over its rivals, then, but it may not be as significant as it seemed back in March. Apple could sign deals with other networks that plan to follow HBO's lead -- including Showtime -- but what it really needs is better hardware.

According to BuzzFeed, Apple plans to unveil a next-generation Apple TV at its Worldwide Developers Conference in June. That could give it a better chance at dominating the nascent set-top box market than temporary, exclusive deals that aren't so exclusive.

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.