Evan Schuman's StorefrontBacktalk

The store knows the customer is there. The customer gets free Wi-Fi. Customers who aren’t in the loyalty program can’t use the Wi-Fi, so it’s an inducement for them to sign up. It also makes it possible to spot Wi-Fi freeloaders—if a loyalty customer uses lots of bandwidth but doesn’t buy anything, you know what kind of “customer” this is.

And none of this requires a mobile signal, so mobile dead spots aren’t an issue (and customers won’t have reason to complain about you burning through their data plan).

In addition, touching phone to kiosk is an opt-in, so customers won’t feel like they’re being spied on or deluged with unwanted offers. Don’t want to be bothered today? Just don’t tap.

On the other hand, there’s a privacy quagmire waiting to happen. Even though a federal appeals court recently ruled that tracking customers in public places is legal, you’d have the ability not just to follow customers around the store but to eavesdrop on everything they do through that network connection. You’ll need a clear, tight privacy policy that you really adhere to. Eavesdropping on people’s comparison shopping or e-mail could put you in an unpleasantly Google-like position, especially if you’re scooping it all up as CRM data.

Connecting in-aisle self-checkout to your CRM system has multiple advantages. Not only can you track what they’re buying, but you can also use that CRM history to decide whether they should be waved past the Loss Prevention people at the door—which would give do-it-yourself checkout the advantage of being faster for customers.

For chains, the advantage to hooking up with customers this way is that it doesn’t require inventing any new technology. And it doesn’t need mobile operators, Google, PayPal, Apple or card brands. You’d get to keep all the CRM data yourself. Plus, it would start getting customers comfortable using their phones for something more than looking for cheaper prices.

It would also turn in-store Wi-Fi into a clear CRM advantage instead of the current hope that maybe someday someone will figure out a good reason for offering it.

And, just maybe, retailers would actually get some benefit out of all the NFC-enabled phones and tablets that are supposed to be pouring from carriers over the next few years. Getting customers to pay that way is still looking as far off as ever; there’s just not enough benefit to them to quit swiping.

But free Wi-Fi? That might do it.