Evan Schuman's StorefrontBacktalk

Walmart has started a trial in three cities where shoppers can E-mail photos of competitors’ receipts, inviting Walmart to do its price comparison without the shopper ever having to actually walk into a Walmart. This clever gambit shares some of the strategy of its online cash program, where the chain didn’t want to lose online shoppers merely because they didn’t have—or didn’t want to use—a payment card.

In this trial program, called logically enough the “Receipt Comparison Tool,” the idea is to showcase hopefully lower prices to consumers who don’t want to walk into a Walmart store. (It’s not like such hesitation is totally unwarranted.)

It’s sort of a Missouri approach, with the shopper in effect saying, “Show me. I like my store. But if you show me concretely how you’d charge me less for the same stuff, I’ll drive over to your store quickly enough. But you show me first.”

On the practical side, the move—which started mid-August—collects E-mails from prospects (potentially for future promotions) and then associates those prospects with specific products of interest.

Walmart has not announced the list of retailers it will compare its product pricing with, which puts consumers in a frustrating position. Many will go through the effort of taking a picture of their receipt, filling out the Walmart form and submitting it—only to then be told they needn’t have bothered, because that retailer is not eligible for the program.

Why not announce the list, so Walmart could avoid alienating some of the very customers it is trying to woo? Could the extra data from all those don’t-have-a-chance submissions really be worth that alienation risk?

This process is quite complex, because Walmart does two fairly common things for its in-store pricing. It localizes pricing, so one store in one neighborhood could have different pricing than a store in another area, and it updates pricing throughout the day based on various issues, including supply and demand.

This means quite a bit has to happen with that receipt. First, the merchant must be identified—such identification is not in any uniform spot—and matched against Walmart’s confidential list of retailers that it will compare against. Second, the items must all be identified, which is not necessarily easy, given the huge number of rather cryptic codes many retailers—especially smaller ones—use.

Next, the system must identify the nearest Walmart to that location (relatively easy). It must then do a lookup to determine what the pricing was for that item at that specific store at that specific date and time. That’s one of the reasons for a seven-day limit. This database is huge enough as is, let alone if it needed to record every item’s price for every store for every hour going back months.

“We do have to go through and use various tools to—in real time—cross-reference the prices,” said Deisha Galberth Barnett, a senior director for Walmart media relations.

Walmart’s marketing goal with this program—to reinforce its pitch that it delivers the lowest prices for most items—is especially critical now, given a late August report from Bloomberg that found Target’s prices were actually lower.

Galberth Barnett tried to put the Bloomberg report into a Walmartian context. She legitimately pointed out that pricing changes with various specials and that only a long-term view is meaningful. “We have beaten Target (in the Bloomberg pricing surveys) for the last 10 months straight. In any marketplace, from time to time, you will see a shift like that.” She added that Target has unusual sales, which she said do not ultimately help the shopper. “We don’t do gimmicks,” she said.