Evan Schuman's StorefrontBacktalk

The idea of using mobile POS devices to queue bust is not a new concept, but the belief has always—logically enough—been that the line will accelerate solely based on how many shoppers can be checked out with the mobile units. But, bizarrely enough, one MPOS vendor has discovered that the units are accelerating all of the lines, not merely the ones where the mobile units are being used.

Here’s how that magic works: A couple of MPOS-armed associates approach some of the overflowing lines and announce that if anyone has a payment card and would like to be checked out with a mobile device to please say so, said Jerry Rightmer, president of mobile POS vendor Starmount.

Clearly, any customer who the associates process (they typically start near the front of the line) will cause that line to shorten. But what Rightmer hadn’t expected was that the MPOS announcement would cause almost everyone in all of the lines to take out their payment card, in the hope of being checked out faster. It’s the act of having their payment card in hand that accelerated the lines quite a bit beyond what a couple of MPOS-enabled associates could possibly do.

It’s yet another wonderful example of unanticipated consequences. No matter how much testing is done, technology deployed invariably will impact—and influence—shoppers in unimaginable ways. It’s not quite the butterfly effect, but it’s close.

Think about how digital shopping devices increased basket sizes, because shoppers on a tight budget spent more. The reason: Those shoppers tended to round up prices in their heads, so a $100 budget would translate to a roughly $93—$94 purchase. When the computer calculated everything to the penny and did not round up, the average purchase for those same $100-budget shoppers averaged much closer to $97—$98.

Or IHL’s wonderful self-checkout diet plan. That’s when the research firm figured out self-checkout customers were so absorbed with the self-checkout process that they didn’t focus on the impulse items in the lane and impulse item revenue plummeted. (The diet part? Many of those impulse purchases were candy.)

Chains are just now starting to discover the impacts of MPOS and consumers widely using mobile. What about mobile payment? If—OK, when—that takes hold, how will that impact purchases in unintended ways?

As for queue busting, the moral of the story is that technology can help move lines a little, but legions of unrealistically optimistic customers will do a lot more good. It’s sort of like the economy.