Roku has more users than Google Chromecast and Amazon Fire TV - and Apple is well behind them all

Roku is set to topple Google, Amazon, and Apple as the most used connected-TV brand in the US, according to a new study from research firm eMarketer.

The streaming company will have 38.9 million monthly users in the US this year, eMarketer says. That's slightly ahead of Google's Chromecast dongles, which will have 36.9 million monthly users, and Amazon's Fire TV devices, which will have 35.8 million monthly users. eMarketer said Chromecast was the market leader last October.

Well behind those three is Apple. The iPhone maker's Apple TV streaming boxes are tipped to have 21.3 million monthly users in the US this year.

That gap could only widen in the coming years: eMarketer predicts Roku will have as many as 69 million monthly users in the US, while Apple TV will have just over 25 million. Google and Amazon are predicted to have 64.6 million and 62.6 million, respectively, which would keep this a three-horse race.

It's worth noting that these figures are estimating the number of users for each platform, not how many devices each company has sold. Roku said earlier this month that it now has 15 million monthly active accounts; the study considers that many of those accounts have multiple people using them.

It's also not a huge surprise that the four major players rank the way they do. The study notes that Roku's advantage is how widely available it is, a strategy that's possible because the company isn't incentivized to push a specific platform the way Apple, Amazon, and Google are. (Amazon uses its Fire TV devices to strongly push users toward its Prime Video service, for instance.) Roku has also grown out its "Roku TV" program, in which various TV manufacturers bake the Roku interface right into their TV sets. Amazon recently started a similar program.

Roku, Amazon, and Google also sell streaming devices at much lower prices than Apple does. While the Apple TV starts at $149, the other three brands have streaming dongles that start in the $30-40 range, with higher-end devices available as you go up the price ladder. Those higher-end devices also include advanced features like 4K and HDR support; Apple TV, despite costing more, does not. (Though it might soon.)

It's likely that Apple makes a higher profit off each streaming device sale than its peers, and the company did patch up a major Apple TV gap by announcing Prime Video support earlier this year. But it seems safe to say that Apple isn't convincing people to pay the premium for its streaming devices the way it has with its smartphones.

Roku, meanwhile, will likely welcome the study as it reportedly plans for an IPO later this year.