Amazon (AMZN -1.64%) wants to control a little piece of your home.

Last week, the company introduced Echo, a sort of personal assistant meant to function as a life organizer. Amazon explained how the device will work on a web page introducing it:

Amazon Echo is designed around your voice. It's always on -- just ask for information, music, news, weather, and more. Echo begins working as soon as it hears you say the wake word, "Alexa." It's also an expertly tuned speaker that can fill any room with immersive sound.
Basically, it's a cool speaker with a built-in voice assistant that works like a well-focused version of Apple's (AAPL 1.27%) Siri or Microsoft's (MSFT 0.37%) Cortana. Instead of being an anything for anytime assistant like the phone offerings, Echo is built around being useful in a home, It does everything from acting as an alarm clock to helping build a grocery list, and delivering weather forecasts.The device is not total home control, and it's not a robot, but if it delivers what it promises, it's a step in that direction.

Amazon's Echo is part speaker, part voice assistant. Source: Amazon. 

How does it work?
Amazon's Echo has an array of seven microphones, which Amazon says "use beam-forming technology to hear you from any direction." Noise cancelling technology also allows the device to hear you even when it's playing music. Echo also has a 2-inch tweeter, a 2.5-inch subwoofer, and a "brain," which the company says learns the more you use it.

"Echo's brain is in the cloud, running on Amazon Web Services, so it continually learns and adds more functionality over time," the website says. "The more you use Echo, the more it adapts to your speech patterns, vocabulary, and personal preferences."

While Echo is meant to be based in the home, it's also supposed to be useful when you are out. It comes with a free companion app that works on the company's own Android-based Fire Phone and other Android phones. Apple and Microsoft Windows users will have to settle for a broswer-based version. The app lets Echo users remotely manage alarms, music, shopping lists, and more.

Will it be useful?
While virtual assistants like Siri and Cortana have captivated the public, in most cases, they have not proven to be particularly useful. Echo is an interesting prospect because its price -- $99 for Prime members for a limited time, and $199 for the general public -- makes it attractive, at least at the lower price, just as a voice-operated speaker/music player. At launch, it will offer hands-free voice control for Amazon Music, Prime Music, iHeartRadio, and TuneIn. It also allows for Bluetooth-based streaming for services including Spotify, iTunes, and Pandora from a phone or tablet. 

As a virtual assistant, Echo, which has not been released yet, looks to have the potential to be useful, but how well it works will determine whether it's a value add or a gimmick. Being able to yell out "Alexa (the name that activates the assistant), we need decaf coffee," and have it add the item to your grocery list seems excellent in theory. In reality, though, its usefulness will depend upon nuance. If it learns the brand, package size, and other specifics for my coffee order, then it's making my life easier. If it's merely taking a note, then it's little more than a tricked-out tape recorder.

Echo also has the challenge that it's not keyed to any specific voice, so my 10-year-old saying "Alexa, buy Cookie Crisp," would carry as much weight as my wife saying "Alexa, buy Cheerios." That's easy enough to remedy if we're using the info to go shopping, but less good if we're using Echo to order directly from Amazon.  

This voice assistant seems like the beginning of the world promised in science fiction. It's technology straight out of Star Trek, and the only challenge is making it work. If saying "Alexa, wake me up at 8 a.m." results in an alarm at the asked-for time, then Echo can become a valuable tool. If the same statement results in the device playing Wham's Wake Me Up Before You Go-Go, it's a whole lot less useful.  

How well does it have to work?
Unlike Siri, which is an add-on to an already-successful product, Echo will almost certainly fail or succeed based on how useful its voice assistant proves to be. The fact that it's a pretty cool speaker/music player at a reasonable price may buy Amazon a little time to perfect the voice features, but if they don't deliver, then nobody will buy Echo beyond the most devoted Amazon fans and other tech early adopters.

Echo has not been released to the public yet -- Amazon is collecting emails of interested buyers and promises that, "If selected, you will receive an email with an invitation to purchase in the coming weeks." The device has also not been sent to the media yet, and as of the morning of Nov. 10, no major tech sites had posted a review of it. Whether it succeeds like the Kindle tablet, or bombs like the Fire Phone won't be based on what Amazon says it does, but by what it actually does.

If Echo delivers on what Amazon promises, then it might have created the first product in a new category of home-based voice assistants. If it doesn't work as advertised, Echo may well be the Apple Newton -- a product that foretold of new technology, but was not good enough to lead the way.