Amazon has added Prime Now rapid delivery voice ordering to its Alexa-powered family of devices.

That means owners of any Alexa device — whether it is Amazon Echo, Echo Dot, Amazon Tap, Fire Tablet, or Fire TV — simply have to say, “Alexa, order (product) from Prime Now.” Alexa will respond with an exact product that matches the general ask. Orders can feature multiple items, and Alexa can recommend complementary items based on what is already in the order.

Prime Now products are available for free, two-hour delivery, and Alexa is in charge of picking the closest available delivery window.

Voice-activated rapid delivery is now available for Amazon Prime customers in more than 30 cities. In three cities — Seattle, Columbus and Cincinnati — Alexa-based Prime Now orders can include beer, wine and spirits as well.

Amazon released this video promoting the new service:

Amazon points to a variety of scenarios where it thinks people will see the value voice-activated Prime Now ordering. Sick people who can’t make it to the store and need some cold medicine, parents who have their hands full with a baby and a host of a game night who doesn’t want to leave the party are all examples of potential users of the new feature, according to Amazon.

“We’re excited to offer the full Prime Now catalogue with Alexa, including tens of thousands of items, which allows you to refill everyday essentials you’ve just run out of like diapers or dish soap, or cater to unexpected guests with merlot and ice cream, all without ever leaving your house or even getting up from the couch,” Assaf Ronen, vice president of voice shopping, said in a statement.

There are a few limitations, however. Users can’t complete in order through Alexa that they began on the Prime Now app. And, Alexa can’t track delivery progress for you. Customers also can’t place an order that includes both Prime Now items, and regular Amazon items.

Amazon has an early lead in the voice assistant market, thanks to Alexa and her more than 10,000 skills. Amazon has been adding Alexa to more of its own devices, and the company is now going after the smartphone market. Last week, Amazon announced plans to bring Alexa to iPhones and eventually Android devices.

Analysts believe that Alexa’s skills will pay off for Amazon. A recent analysts from RBC Capital Markets estimated that sales of Alexa devices could hit $5 billion by 2020, with another $5 billion in annual revenue predicted to come from shopping done via the voice assistant.

Despite those skills, Alexa still has much to learn. Amazon senior principal scientist Nikko Strom spoke at the AI NEXT tech conference in Bellevue, Wash., last weekend, where he said the next step for the digital assistant is comprehending emotion and intonation so that it can understand what people mean, not just what they say.