It was Saturday morning, and Melissa was making a stop at her local Walmart to pick up a few things. As usual, she parked as close as she could and walked the familiar pavement up to the well-lit store entrance. Upon entering, her eye was drawn to something unfamiliar in the lobby. Standing against what used to be an empty wall was now a large, colorful, slightly unusual-looking vending machine. Intrigued, Melissa approached it—and immediately noticed a couple of things. For one, the machine was completely stocked with only one product—bright green Cascade dishwashing detergent samples made by Procter & Gamble (P&G). Second, in place of the normal mechanism by which you would insert coins or bills to make a purchase, there was a large, rectangular, color LCD screen that welcomed her with the line, “Press here to get your free sample!” Her finger instinctively reached out and pressed the screen where instructed. The screen promptly displayed:
Using your smartphone, please visit our product’s Facebook page. After you log in, go to this URL—http://cascade.facebook.com.
If you Like our page, we’ll vend you a free sample of our new Cascade dishwashing detergent right here, right now!
Melissa was hooked. She retrieved her iPhone from her pocket . . . and paused. Was this strange new transaction worth it? By pressing that “Like” button, she would be telling all her Facebook friends that she, in fact, liked this promotion. After examining the machine some more and ...