Have you heard of Roku? The first box that brought streaming videos from Netflix (Nasdaq: NFLX) to the big-screen TV in living rooms across America has only been available online so far, making it kind of tough to stumble across the device if you're not glued to a Web browser. Yet the device hit its millionth user in 2010, riding the coattails of Netflix's 20 million users as well as a portfolio of additional content that includes Amazon.com (Nasdaq: AMZN) On Demand and the network-sponsored Hulu Plus service.

That's about to change in a hurry: Roku boxes have just hit store shelves at your local Best Buy (NYSE: BBY), Fry's Electronics, RadioShack (NYSE: RSH), and even BJ's Wholesale Club (NYSE: BJ). Putting the gadgets in front of casual consumers is likely to boost sales significantly, as the darn things are a lot cheaper than buying a Blu-ray player just for its online video features.

The closest thing in retail stores so far has been Apple's (Nasdaq: AAPL) Apple TV boxes with their similar price tag and feature set, but you can't get those at RadioShack or Fry's and not everyone enjoys the iron-fisted lock-in to the iTunes ecosystem.

More Roku sales should translate into higher consumer awareness of online video services in general and of the Big Three -- Netflix, Hulu, and Amazon -- in particular. I cut my cable and bought a Roku months ago, and I really don't miss the hassle of TV schedules. It's not perfect yet, but software updates can work wonders down the line. It's already good enough that I wish I could buy stock in Roku, the company, or at least peruse its financial statements. Well, if Pandora is going public, then Roku can't be far behind.

Will Roku be the next impulse-buy success story? Add Netflix and Amazon to your Foolish watchlist, and you'll be sure to hear all about it.

Fool contributor Anders Bylund owns shares of Netflix but holds no other position in any of the companies discussed here. Best Buy is a Motley Fool Inside Value choice. Apple, Amazon.com, Best Buy, and Netflix are Motley Fool Stock Advisor recommendations. The Fool has written puts on Apple. Motley Fool Options has recommended a bull call spread position on Apple. The Fool owns shares of Apple, Best Buy, and RadioShack. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. You can check out Anders' holdings and a concise bio if you like, and The Motley Fool is investors writing for investors.