When Laura Schnurr tried out scan and go at Walmart in Ancaster, Ont., she was immediately hooked. The new technology allows customers to scan and tally up their items while shopping, saving them time at checkout.

"When I go up to the checkout, it's just bing, bang, boom, I'm done," Schnurr said. "I am addicted."

Starting Monday, Walmart will roll out scan and go in 20 more Canadian stores. It's the latest offshoot of the self-checkout craze, fuelled by retailers' attempts to curb costs and make the in-store shopping experience as painless as possible.

"People's patience for waiting is declining rapidly," said Jeff Doucette, of market research company Field Agent Canada.

"It's like, why would I go to [a store] and stand in line for something when I can just order it and it will show up tomorrow?"

Customers can scan items while they shop, cutting down their checkout time. (Field Agent Canada)

This is how scan and go works: shoppers pick up a portable scanner in the store and scan the barcode on their items before putting them in the shopping cart.

The scanner tallies the bill and customers bag their items themselves. They can either pay at the cashier or use self-checkout. "Your checkout takes seconds," said Schnurr.

Putting cashiers out of work?

In the U.S., Walmart has made the process even faster by replacing the scanner with a mobile app. Customers in more than 20 participating locations can now use it to both scan and pay for their items on their smartphones.

They get to bypass checkout and just have to show their receipt to an "exit greeter."

At some U.S. Walmarts shoppers can download an app that allows them to both scan and pay for their items using their smartphones. (Walmart U.S.)

Walmart Canada also aims to offer customers the app, which is catching on with some U.S. shoppers.

"It was awesome. I didn't have to stand in line, which is the wors[t] part of Walmart. I didn't talk to a single worker," posted Nate Look on Facebook this month.

But others fear the technology will lead to the demise of the cashier, forcing shoppers to do all the work.

"I don't support scan and go," posted Brenda Hauglum. "People need jobs."

Even though Schnurr likes scan and go, she too is concerned about putting cashiers out of work, so she always goes to one to pay her bill.

"I don't want to make them completely redundant, so by going to the cashier I don't feel as bad," Schnurr said.

According to Walmart Canada, scan and go has not resulted in any job losses and the retailer is offering it purely to make shopping more convenient.

"It's a customer service initiative," said spokesperson Alex Roberton.

Some shoppers fear the Walmart scan-and-go app will lead to the demise of the cashier, forcing shoppers to do all the work. (Chris Hondros/Getty Images)

There's no doubt stores are moving increasingly toward automation. By the end of 2016 there were 255,000 self-checkout machines in stores around the world. That number is expected to reach more than 400,000 by 2022, according to London-based research and consulting group RBR.

Companies are also rushing to find other ways to automate the shopping experience.

Amazon is running a pilot project, Amazon Go, at a grocery store it has set up in Seattle. Shoppers don't even need scan their items — they just take what they want and walk out, thanks to technology that detects when products are removed from store shelves.

Customers are billed via their Amazon accounts.

But Field Agent's Doucette warns we're a long way off from a cashier-less world. Amazon Go is still in its testing phase and is currently only open to employees.

By the end of 2016 there were 255,000 self-checkout machines in stores around the world. (CBC)

Also, self-checkout doesn't appeal to everyone and has its drawbacks: it can malfunction, it can't do price checks or price matching and it can be a hassle when buying big items.

"We were just recently at Ikea, and Ikea offers self-checkout," Doucette said. "But no one was really using it because you're dealing with these big boxes of flat furniture."

He believes that, for now, systems like self-checkout and scan and go will appeal to certain shoppers who see doing some of the work themselves as actually more convenient.

"There'll [still] be people that just want to do it the old way."