Amazon's voice-recognition-based gizmo called Echo may soon become the next great thing as believed by many tech experts. Experts based their assumption on its rapid rise in popularity, the gadget being now one of the most sold-out items on the e-commerce giant's site.

Amazon Echo is a voice-controlled, screen-less household computer expected by analyst to surpass smartwatches and fitness trackers in popularity as people become more accustomed to it in their homes. Plus, the gadget is extremely versatile and it can be constantly improved with new functionality.

It integrated vocal assistant called Alexa which looks more promising than Google Now and Apple's Siri. You can order a Uber ride via Alexa, add new items on the shopping list, or perform simple tasks as reordering popcorn with a single voice command.

Tech writer Farhad Manjoo has high praise for Amazon's Echo: "Amazon seems on the verge of building something like Iron Man's Jarvis, the artificial intelligence brain at the center of all your household activities," he writes in the New York Times.

Reportedly Amazon has worked very hard on making the Echo faster. NYT reported that earlier the device used to take 8-9 seconds to respond, however now the response time has been almost reduced to 1,000 or 1,200 milliseconds

"It's one of the most sold-out things that I see on Amazon," said Scot Wingo, the chairman of ChannelAdvisor. "It's an unusual thing for Amazon to be out of something, but for the Echo, it's usually in stock just for a couple weeks before it goes out of stock for a few days - so it feels like they're having trouble making enough of the devices."

While Amazon doesn't release official device sales numbers, consumers appear satisfied with the Echo; Amazon's website has the device with an average 4.4 out of 5 stars from over 33,000 reviews. As regular Amazon users, this is rather unheralded.

The Echo runs around $180, but Amazon also released two new versions last week: a portable version and one that can plug into an existing speaker.