“It can be extremely appropriate for all kinds of products or services,” she says. “You’d think that it’s a silly strategy: You have a new product and people want it, so why would you make it hard to get? But it can increase the desire and the likelihood that people will try to buy it right away.” She adds that for some consumers, the perception of exclusivity can also make a product seem more valuable and increase the tendency to buy — and it’s all tied to how our brains register danger.