When you see words like "buy now" or "flash deal," while shopping, take caution, say our experts. Retailers use a sense of urgency to push consumers to make quicker shopping decisions, Vines says. They don't want you to think too hard about the purchase. This strategy also relies on shoppers' fear of missing out, Weekes says. It makes people think, "if I don't purchase this right now, I'll never get this deal again."