Evan Schuman's StorefrontBacktalk

Although the Peapod mobile app features some 12,000 SKUs, just 70 items are being used in the Chicago trial and even fewer—about 45 items—are being tested in Philadelphia.

Part of the challenge was logistics. For comfortable QR interactions, the images need to be at eye level and about 5 feet from where the shopper is standing. Much more than 5 feet and the phone won’t grab the code properly; much less than 5 feet and the shopper can’t see enough of the super-sized image. That had to be worked into a limited train station—or subway—space.

The small sample of products displayed were chosen based on their perceived convenience. Items included milk, bread, Coke, water, dog food, diapers, paper towels, Kleenex and ready-to-heat meals.

“We wanted to showcase convenience products, and then let (the customers) continue shopping in the mobile app” while on the train, Margolis said.

One debated point was the technology to be used. QR codes have become popular with retailers that want to do quick mobile trials. Indeed, Home Depot and Macy’s in October 2011 were exploring using QR codes that would display different things based on a shopper’s CRM profile. And JCPenney got QR clever with an effort in November to track where gifts ended up.

But as much as retailers love QR for its ease-of-use and platform agnosticism, consumers have been confused and generally unenthusiastic.

Peapod was practical about the QR code decision, after initially briefly considering NFC. “Our Web team decided (to use QR) because it was the easiest way to track” shopper activity, Margolis said, adding that the relatively short duration of the trials made it a no-brainer. It’s not as though QR codes would disappear by the end of the trials.

The trials have only been supporting two smartphone platforms (iPhone and Android), and Margolis said it’s been no contest about which platform was more popular. “Thus far, it’s been 90 percent iPhones and 10 percent Android,” she said.

The products are using the same UPC codes that Peapod uses on the app, so it’s easy to keep track of products purchased.

When observing consumers trying to use the QR codes, Margolis said the age differences were extreme. “All of the young people going through, they had no problem,” she said, adding that she witnessed one customer (“a guy probably in his 50s”) who was struggling.

He “was trying to do it and he was asking someone else for help. The problem seemed to be that he wasn’t holding his scan steady enough,” Margolis said.