Don’t discount the power of an “exclusive” sale.

Companies are getting more creative in selling off seasons-old product or discontinued wares — and hosting private sales has become a popular way to tempt shoppers to buy in.

KREWE, a New Orleans-based optical brand that caters to celebrities like Blake Lively, Beyoncé, Gigi Hadid and Selena Gomez, just ran its annual “Once-a-Year Private Event,” in which it shut down the website and required an email address for access to significantly discounted specs. And its timing couldn’t have been better, as Lively wore Krewe sunglasses to the Met Gala earlier this month.

“Sales are not for everyday, or for everyone. KREWE was founded on the philosophy of doing something unexpected from a place no one would expect,” Stirling Barrett, founder and creative director of the company, told Moneyish. “Our customers are loyal and frequently come back asking what’s next.”

Lilliana Vazquez, style expert and founder of Tesoro Collective, told Moneyish that because sales have become so commonplace, consumers have become desensitized to them. “The private sale strategy can create excitement and a sense of urgency to shop in an all too crowded promotion marketplace,” she said. “People are naturally drawn to exclusivity of any kind. ‘Private’ sales are a great way to make your customers feel special and unique, and like they have ‘access’ to something that others don’t.”

So fashion designer Christy Dawn announces discounts via Instagram, automatically giving her followers a leg up in being the first to hear about specials happening online or in-store. Fashion label Rag & Bone has also been known to operate private sale events, and Apple has notoriously blocked their website from retail activity prior to launching a new product. Last week, The Mighty Company used an Instagram poll to ask their followers where they’d rather have a sample sale: Los Angeles or New York. “Even though we knew we’d more likely do it in our stomping ground of LA, I was really just using the poll to test attendance in each city,” Jessie Willner, founder and creative director of the company told Moneyish. Following the poll, Willner says there was a direct uptick in newsletter sign-ups, probably because of people wanting first access to any additional news.

“Experiences and exclusiveness are two major factors of our current retail landscape. Shoppers want to be entertained and also have custom experiences curated for them,” fashion writer and creative consultant Melissa Magsaysay told Moneyish. For retailers, Magsaysay says non-traditional commerce is beneficial because the bespoke events that they create for the customer are also prime testing grounds for seeing what’s best for their brand and product. They’re also able to control their message and better monitor the customer’s buying behavior.

Considering 1.66 billion people worldwide purchased goods online in 2017, according to Statista, and global e-retail sales are projected to reach $4.48 trillion dollars by 2021, there’s a lot of money at stake. Popular Science suggests that deals are designed to draw in vulnerable shoppers. “Retailers know that if they throw the word “free” out there, consumers will lap it right up,” the magazine reported last year.

Jill Dvorak, senior director of digital retail at the National Retail Federation told Moneyish that these private sales grew out of the flash sale sites where you had to log in to see discounts and sales. “And whether they actually require a login or not, a lot of companies label their sale as ‘VIP’ or ‘exclusive’ to make people feel emotionally included and invited to something,” she said.

And “sale” is also a four-letter word for many luxury brands. When a high-end line needs to move old inventory, they prefer to do it via private sales or sites known for selling luxury goods, since promoting and widely publicizing “sales” can diminish a brand’s value, according to Sara Skirboll, the shopping and trends expert at RetailMeNot. Brands like Kate Spade and Tory Burch will lock the sales portion of their websites and require either an email address or a code for entry. Retailers like Nordstrom offer an anniversary sale exclusively to their credit cardholders.

But other companies will make their sales available to the general public while trying to make it seem like they’re catering to a select group — because some of these so-called private sales aren’t actually as secretive as retailers make them seem.

if you’ve ever opted into an email list or have signed up for a brand’s newsletter, for example, invitations to special shopping events and sales have probably flooded your inbox — and everyone else who subscribed. “Signing up for a store’s newsletter can mean exclusive coupons and savings, but it also means receiving constant communications,” Julie Ramhold, consumer analyst with DealNews told Moneyish. “Especially around the holidays, these communications will pick up and will often include one-day sales to try to persuade you to shop early.”

One tactic Dvorak thinks has worked really well is Lilly Pulitzer’s “After-Party Sale.” Virtual numbers were handed out to shoppers, like you’d receive at a deli counter,” said Dvorak. Instead of flooding (and possibly crashing) the site all at once, 100,000 people waited in a digital line for their turn to enter the sale, and once “inside,” shoppers had 30 minutes to complete their purchase. “When it comes to scarcity, there’s nothing that gets someone to move faster than thinking something might run out,” Dvorak shared.