Last week I wrote about the authenticity of long lines, using Supreme and Everlane as contrasting examples. Long lines and limited scarcity are part of Supreme’s DNA, while they are out of place for a basics brand like Everlane. Either way, I noted that the line itself—like supply and demand—is contrived and easy to manipulate for the company’s benefit.

Dave Barton, an Espresso subscriber who runs the optical company David Kind, replied to the piece asking about the corollary to online lines, which are normally in the form of waitlists—a great point to consider given the massive number of brands navigating the digital economy.

As ecommerce has taken off, it’s become easier for brands to track what their customers want, but much harder to anticipate inventory needs. Planning is always a challenge. While wholesale has been derided for many reasons, it always came with the advantage of somewhat consistent demand forecasting. Despite technicalities such as chargebacks and sales, if a store ordered 1,000 units of a product, the brand had months to plan for and produce the products needed to fulfill the order.

But for direct-to-consumer brands, especially those early on in their life cycles, there’s no way to know who will show up to buy something one day over the next. As a result, many of these brands have turned to waitlists, where customers can leave their information in order to receive notifications about future product releases, allowing the brand to plan its inventory off of some sort of data.

Mansur Gavriel, whose bucket bag was the it-bag for a number of years, was one of the most prominent adherents of the waitlist. Demand vastly outstripped supply in the brand’s youth, as well as its supply chain capabilities, and the company used waitlists to manage this demand as it scaled. While a long wait for products made the brand resonate, it seemed at the time like a real solution to a problem known to viral entrants to the market: Glossier had similar experiences with some of its products early on, Harry’s had a 100,000 person waitlist at one point, and so forth.

But waitlists have wide-ranging effects on customer opinion, and perception mostly comes down to how the brand handles and communicates their purpose to shoppers. For brands that are learning to scale up their supply chains, the waitlist is one of the least-detrimental ways to capture demand that cannot yet be fulfilled. On top of this, some brands definitely like the clout that scarcity provides, with FOMO driving the numbers even higher. Most shoppers will tolerate a wait if the brand is well-intentioned and makes good-enough products.

However, if the brand starts to overtly use the waitlist as evidence that it is special, and to tout the number of people on the list for promotional purposes instead of trying to work through the issues that caused it in the first place, the waitlist ceases to work in the brand’s favor. This often feels like the “Only three left!” exclamations on Amazon or in dollar stores, evoking the joke from a very bad Adam Sandler movie—I won’t tell you which one—which features a store called “Going out of Business” that forever schemes against its customers.

Waitlists likely will not go away, both because of the nature of direct-to-consumer inventory and the marketing benefits it provides the brand, but companies can be smart about how they use them. Shoppers will likely heed the tactic if a brand is well-intentioned and doesn’t use the waitlist to take advantage of consumers’ interest in its products. Failure to do so will result in short-term gains over the long-term success of the brand.