The next big function to take off on Amazon’s Echo devices will be voice or video calling — which is a way Alexa can reduce the need to have your smartphone on your at all times, said Rohit Prasad, VP and Head Scientist at Alexa Machine Learning.

“If you have not played with calling and the video calls on Echo Show, you should try it because that is revolutionizing how you can communicate,” Prasad said in an exclusive interview with CNBC at an Alexa Accelerator event in Seattle Tuesday night. (The event is dedicating to developing new voice-powered technologies.)

“When you can drop in on people who have given you access — so I can drop in and call my mom in her kitchen without her picking any device – it’s just awesome.” (Amazon added the ability to call mobile numbers and landlines for free onto Echo devices a few weeks ago.)

Amazon doesn’t have a smartphone that lets customers bring a digital assistant everywhere — like Apple’s Siri and Google’s Assistant — and communicating through Alexa devices is one way of reducing the need for a personal handset, Prasad said

“I can easily drop in and talk to my kids,” Prasad says. “They don’t have a smartphone so that’s my easiest way to talk to them. It’s yet another area where Alexa is taking the friction away.”

Asked whether we’d see a smartphone or smart glasses (which are reportedly in the works) from Amazon, Prasad said that he couldn’t comment on the future roadmap but he didn’t rule it out.

“We do want Alexa to be everywhere, so our customers can do their daily tasks with minimum friction and anywhere they need it,” he said.

As for where Alexa and artificial intelligence fit into Amazon’s larger business, Prasad says Alexa could be Amazon’s fourth pillar.

“Jeff [Bezos] has said Alexa could become one of the four pillars. I think we want to get there, still very very early for us.”

He added with a laugh, “we have had a pretty good start.”

Jeff Bezos, in his 2016 letter to shareholders, identified the company’s three main pillars: marketplace, Prime and Amazon Web Services, its cloud computing business. But he also wrote in the letter: “I assure you that we also remain hard at work on finding a fourth.”

Onlookers have speculated that the fourth pillar could be anything from logistics to video content to groceries or Alexa, and Amazon is making big bets in all these spaces.

Prasad noted that five years ago Alexa was just getting started. “Our vision was to build a computer that you can talk to anywhere, built into anything and is accessible to every demand you have and wherever you need it.”

Since then, Amazon has sold 15 million Echo units, according to a recent report from Consumer Intelligence Research Partners. Prasad says that Alexa now has more than 25,000 skills — up from 15,000 at the end of September. Five years from now, users will be having 20 minute conversations with Alexa, he said.

Over the summer, Amazon and Microsoft teamed up to work together to extend the abilities of their voice-controlled digital assistants. Some analysts found it an unusual partnership, but Prasad said it was an easy decision.

“Microsoft has all the office applications around calendars, email – clearly that was a great synergistic relationship to have on behalf of our customers and so that was a fairly easy decision for us to make because we want to do the right thing for our customers. Alexa talking to Cortana is going to be better for our customers.”

When asked if Amazon was open to partnerships with other competitors in the AI space, like Google and Apple, he said he couldn’t comment comment on whether anything was in the worlds, but said he’d be happy to work with both companies.