For many people, one of the best parts of Thanksgiving is grabbing a newspaper to check out the retail circulars for Black Friday deals. The internet has influenced this tradition to an extent—many of the Black Friday ads are leaked online days or weeks in advance—but there’s still an undeniable psychological pull behind this national shopping day. For some retailers, the holidays can make up roughly a third of their annual revenue, with consumers spending $720 billion on Black Friday. Clearly, they have mastered the art of prying open our wallets.

How do they do it? According to a recent piece by Chavie Lieber at Vox, Black Friday is an exercise in shopper manipulation. Retailers typically begin by blanketing their email lists with notices of early sales beginning in late October and November, squeezing in valuable extra weeks out of the shopping season. Known as “Christmas creep,” it promotes Black Friday less as a single day and more of a month-long atmosphere.

Retailers also depend on promoting a level of anxiety among shoppers by depicting deals as being singular or exclusive. Insisting a deal is only good on a certain day or window of time creates a sense of urgency—even if that deal might crop up elsewhere during the year. Special “deals” might actually be just a method of creative pricing. Buy One, Get One, or BOGO, infers two items for the price of one, for example, but buying one item at regular price might not be much different than buying two on sale another time. Still, consumers are primed to respond to “free” without stopping to think if they’d consider the list price for the single item a good deal without the bonus.

A 2017 Money.com report made mention of the fact that many BOGO deals and other promotions aren’t exactly novel. Stores often repeat the same deals from one year to the next, making sure the economics of their promotions are in line with their financial goals.

Despite the hyperbole and convenience of online shopping, consumers still seem to make a ritual out of going out on Black Friday. (A 2017 survey estimated 25 percent of shoppers will head out to fight the crowds.) It’s less about the desire for deals than the competitive nature of the day. Snagging a deal with perceived exclusivity is satisfying. So is heading back to your car with bags of stuff you may never have bought otherwise.

Shoppers that are task-oriented feel a sense of fulfillment when they get rung up for an advertised deal. Social shoppers actually enjoy the crowds and feel a sense of camaraderie with bargain-hunters.

How you feel about Black Friday depends on what you’re looking to get out of it. If you’re after once-in-a-lifetime deals, you might be disappointed to find that you can save money during other times of the year. But if you treat the phenomenon as a challenge or a social gathering, then you’re likely to walk out of a store happy. If you're upbeat about having overspent, then retailers—and all of their subtle psychological tricks—have done their job.

[h/t Vox]