It's the little streaming box that could.

Roku Inc. has gone from being a Netflix Inc. (Nasdaq: NFLX) hardware spinoff to a powerhouse brand in its own right. According to a filing with the Federal Communications Commission (FCC) , the streaming platform company had an estimated 7.6 million monthly active accounts as of the end of September. And that's up from about 7 million active accounts only nine months earlier.

The company has introduced several product iterations (including the Roku streaming stick), and it's working with manufacturers to embed its operating system in select TV sets.

Roku is also the third-party hardware company that everyone wants to partner with. (See Charter Parks Its App on Roku and Roku Hits 10 Million Mark – Now What?)

Why? Because it has no other agenda; no programming of its own to sell and no wish to make an end run around traditional service providers.

Want to know more about the impact of web services on the pay-TV sector? Check out our dedicated OTT services content channel here on Light Reading.

That said, Roku does have serious competitors. Here's what Apple Inc. (Nasdaq: AAPL), Google (Nasdaq: GOOG) and Amazon.com Inc. (Nasdaq: AMZN) bring to the table.

Apple TV: Apple's streaming box dropped to fourth place in devices shipped, according to a report by Parks Associates in August. But that was before Apple introduced its newest product in September along with the TV operating system, tvOS. Apple may have put a hold on plans to launch a video service, but it counts 11 million developers in its mobile community, which gives it a lot of influence in the emerging TV software space. With Apple, where software goes, hardware follows. (See Roku Reigns in Streaming Market, Apple Brings tvOS to Apple TV and Apple Presses Pause on OTT TV  Reports.)

Chromecast: Google's streaming stick gets second place honors in both number of devices shipped and actual in-home usage among media streamers, according to Parks. Chromecast has the advantage of being incredibly cheap ($35 or less), and it was the first to popularize the HTML adapter stick format. Perhaps more importantly, Google is reportedly now talking with content providers about bringing movies and TV shows to its $10-per-month subscription YouTube Red service. A streaming stick and a TV service? Sounds promising. (See YouTube Seeks Slice of OTT Pie.)

Fire TV: And then there's Amazon. Fire TV is a relative newcomer to the streaming media market, but it's got one huge advantage to leverage: Amazon is the king of online retail, and recently it stopped selling both Apple TV and Google Chromecast devices. Looking at the top-selling consumer electronics products on the site just after Thanksgiving, both the Fire TV and Fire TV Stick made the top 10 list. Amazon may have been in third place for units shipped in the Parks Associates' study over the summer, but it's sure to rise after this holiday season. Plus, Amazon's got more original TV content coming. A massive distribution channel and original programming make a powerful combination for Fire TV. (See How Amazon TV Could Own Christmas.)

— Mari Silbey, Senior Editor, Cable/Video, Light Reading