In the name of convenience, US retail giants Amazon and Walmart are pushing their customers to shop by simply reading out their shopping list to a digital assistant.

This opens the door to getting the shopping done while cooking dinner, sorting out the washing and even changing a baby’s nappy – all just by calling out your order to the Alexa assistant on Amazon’s Echo speaker and other devices.

Walmart are jumping aboard as well and will soon offer voice shopping with the Google Assistant on the rival Home speaker system.

Great. Right? Yes, well maybe.

Voice shopping is still new and once you start using it you discover you may not know if it’s offering you the best deal and price.

Digital assistants can’t say much without tiring your ears. Google introduced shopping to Home in February, letting people order essentials from more than 40 retailers like Target and Costco under its Google Express program. Its partnership with Walmart means hundreds of thousands of items will be available to customers in late September.

With websites and apps, many customers place items in the cart, but change their minds before completing the order, said Lauren Beitelspacher, a marketing professor at Babson College in Massachusetts. Voice shopping eliminates those intervening steps.

And with Amazon so far ahead, voice shopping with Alexa is another way of getting you hooked on Amazon. Although Amazon allows some third-party ordering through Alexa, including pizza from Domino’s and hotels through Kayak, general shopping is limited to Amazon’s own store. If Alexa orders nappies for you just as you run out, for instance, Amazon locks in the order before you have a chance to visit Walmart.

“You can’t get away from Amazon,” Beitelspacher said.

“I don’t know if gimmick is the right word, but (voice shopping) is part of a strategy to be omnipresent in consumers’ lives.”

Ask Alexa to buy something, and it presents you with something you’ve bought before or an educated guess based on some undisclosed mix of price, satisfaction rating and shipping time. Amazon won’t provide more details. You can get a product’s average customer-satisfaction rating, but not specific reviews, even on screen-equipped Echo Show devices.

Brian Elliott, general manager of Google Express, says that with most affiliated retailers, personalisation occurs as the assistant learns shoppers’ preferences, but the integration with Walmart will happen more quickly.

In some ways, shopping by voice assistant is a throwback to the days when you were largely limited to what sales representatives recommended at a physical store.

Amazon’s website gives you a lot of information about most products, from colour options and sizes to the specific reasons other customers hated a product you’re considering. You’re able to compare similar items and choose something cheaper if you’re willing to sacrifice some features or take a chance on an unknown manufacturer.

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