The walls have ears, almost literally, when Amazon's (AMZN) Echo is listening. This device and its peers will transform how people interact with media, appliances and even each other at home.

I assumed that the Echo voice-activated assistant would be a $99 paperweight, albeit half the price the paperweight costs people who don't subscribe to Amazon Prime. Instead, it wound up fitting in somewhere between a useful gadget and a member of the family.

Amazon Echo is a black cylinder standing nine inches tall -- about the dimensions of a thin roll of paper towels. Plug it in, sync it with a mobile device via wifi or Bluetooth so it can connect to a wireless network, and it listens in the background for its name (Alexa or Amazon are the only options so far). After someone in the room says "Alexa," a ring encircling the Echo's top shines with a blue light, and it awaits commands. Particularly useful ones include "weather" for a local report or travel forecast; "buy diapers" to add such items to a shopping list in the accompanying mobile app; and "play classic rock" to stream songs from Amazon or play music from your own stored library. It can also look up factual information from services such as Wikipedia, set a timer, create reminders and respond to other requests.

Right now, the voice recognition is impressive. As far as the commands it can respond to, it is often underwhelming or frustrating. Sometimes it wants to play music samples rather than stream music, or it can't get the basic gist of what I'm asking. All that, however, is a matter of Amazon updating software. And the limited features are still routinely useful, especially for a $99 device.

The potential is much greater. It's easy to imagine a near future where Echo can respond to queries such as, "Please turn down the lights and lower the thermostat by a few degrees;" "Recommend a dark comedy that I can binge watch on Amazon Prime;" "Which items on my shopping list are on sale?;" "Add the ingredients I need to make a chocolate birthday cake from scratch to my cart and deliver them by 5 p.m.;" "Give me gift suggestions for my daughter's birthday;" and "Buy the book '50 Shades of Grey' and deliver it to my mother's Kindle." Many such queries are commercial in nature, and given Amazon's growing advertising business, sponsored recommendations should be part of the roadmap for making Echo an even greater profit driver.

The most surprising facet of Echo is that it isn't a paperweight at all. When I first read about it, it seemed pointless. Why bother adding another device to replicate most, if not all, of the functionality of a smartphone? Yet what makes the Echo beautiful is how it fades into the background and becomes an almost hidden part of the room. Taking a smartphone out of one's pocket doesn't require a lot of effort, but it does require shifting attention to the device. With Echo in the background, taking an action is practically as simple as thinking about it.

Consider a scenario at a dinner table where you might not want to have any devices out. If your partner asks you, "Are we running low on milk?," it's easier to say, "No, but Alexa, remind me to buy milk tomorrow" than it is to take out the phone and add that to the to-do list. The Echo briefly becomes part of the conversation. I find it particularly useful when playing with my toddler, as that's a time when I am making a dedicated effort not to be distracted by a screen. My daughter was puzzled by Alexa's arrival and initially seemed disturbed by it, but now she routinely points to Alexa and wants me to turn it on to play music.

The Echo is hardly the only entrant in its category. Every couple of months, a new voice-activated assistant seems to become a popular crowdfunding project on Kickstarter or Indiegogo. Each will have access to different services but likely serve similar purposes, and these assistants will become far more popular as homes become smarter and more connected. Amazon Echo could either prove to be the iPhone or the Google Glass in the category -- the first one to catch on and dominate the market, or the most popular entrant that defines a category in which it can't compete.

Voice activation in the home does make sense, it can work, and it will catch on. As it becomes more popular, it could even eat into a bit of the time people spend using various screens. Alexa and her peers will start shaping how people consume media and shop.