The release of the Echo Dot, a miniature version of its home speaker, and the Amazon Tap home speaker highlights how important the voice-controlled Alexa interface is becoming for the world’s largest online retailer.

Share story is putting more eggs in Alexa’s basket by launching two voice-controlled home devices to complement its successful Echo home speaker.

Unveiled Thursday, Echo Dot looks like a flattened version of the cylinder-shaped Echo.

The $89.99 Echo Dot connects with external speakers either via Bluetooth or cable. And, like its taller cousin, it is animated by Alexa, a voice-controlled digital assistant not unlike Apple’s Siri or Microsoft’s Cortana.

Alexa can tell jokes, play music and get stock quotes. It can also answer simple questions (it’s connected to Wikipedia), control some home-automation devices and, significantly, order from Amazon’s online store.

Most Read Stories

Unlimited Digital Access. $1 for 4 weeks.

It’s also an open platform for other companies to build apps on: Now you can order an Uber ride or a pizza by speaking to an Echo.

Amazon calls these apps “skills,” a metaphor for how it envisions Alexa as a perpetually improving platform.

The other Alexa-bearing product unveiled Thursday is dubbed Amazon Tap, a portable Bluetooth and Wi-Fi speaker. Unlike the Echo, it doesn’t need to be plugged into an outlet all the time.

The release of these new products underscores how prominent the voice-controlled interface is becoming for the world’s largest online retailer.

Amazon Echo has been something of a hit, outselling all other home audio speakers on Amazon’s website. The company doesn’t break down how many Echos it has sold, but Chief Financial Officer Brian Olsavsky said in a January earnings call that “we like how Echo’s done.”

The company’s devices business, of which Echo is part, doubled in the fourth quarter from the previous year, Olsavsky said.

Alexa was the star of Amazon’s first ever Super Bowl ad, which featured actors Alec Baldwin and Jason Schwartzman, singer Missy Elliott and retired Miami Dolphins quarterback Dan Marino.

The ad must not have come cheap: 30-second spots in America’s largest sports event were selling for $5 million, according to remarks made by CBS Chief Executive Leslie Moonves during a conference call last summer.

Amazon holds its cards close to its vest, but one can get a glimpse of where it’s putting money by browsing through its jobs site. There again, many chips fall on the voice platform, with hundreds of open jobs related to Echo and Alexa.

The Echo Dot is available in limited quantities and can be ordered only by Prime members using Alexa through a device they own (either the Echo or an Amazon Fire TV that’s also Alexa-enabled).

The Echo Dot means one can extend Alexa’s reach into several rooms of the house for less money than buying several full-sized Echos. The cable and Bluetooth connectivity means one can now infuse a home stereo system with Alexa.

The Tap is like a portable Echo, but unlike the bigger device, it’s not listening all the time.

To conserve battery power, however, the Tap requires people to touch a button on the front of the device to prompt Alexa to awaken and listen for a question or command.

The Echo operates on more energy-intensive technology that allows people to summon Alexa with spoken words heard from as far as 25 feet away.

Amazon is limiting the number of these new Alexa-connected devices one can get, however.

Every Amazon account holder can get up to two Echo Dots or three Amazon Tap devices. But customers can buy as many as 20 full-sized Echos.