In-store advertising can be harder than it looks. Displays with funny names like end caps and power stands are often placed in the wrong aisle--or worse, sit in the storeroom gathering dust. Kraft and Procter & Gamble employ scores of auditors to keep tabs on displays, but that solution is beyond the means of most businesses.

Enter Goliath Solutions, a Chicago company whose new system uses radio frequency identification, or RFID, technology to monitor in-store displays. A credit-card-size RFID tag mounted on the display transmits data to both the retailer and the product maker, verifying that the display is on the floor and in the right aisle. It also tracks sales data, which helps companies measure a display's overall effectiveness.

Some privacy advocates worry that retailers will link RFID data to a customer loyalty system, amassing too much information about shoppers' habits. Fans say that it is a step toward more efficient inventory management, which helps companies keep prices in check. Walgreens plans to deploy the system in 5,000 stores, and Goliath CEO Bob Michelson says it is cost effective for companies of all sizes.

Tom O'Brien, for one, is eager to test the system. O'Brien is COO of Tom's of Maine, a $50 million natural beauty products company. Because 60% of its customers discover the Tom's brand in stores, floor displays constitute its largest marketing expense.

Goliath's system appeals to O'Brien because he'd like to confirm that every display is correctly placed, and also because it would let him test the impact of different displays in real time. "That has huge advantages," he says. "If we could evaluate end caps in five weeks instead of five months, we could generate an incremental $5 million in yearly revenue."