The business model of luxury is heavily dependent on a relatively small number of high-end spenders, and to reach them brands like Gucci and Tiffany & Co. are relying on exclusive access to their designers or one-of-a-kind offerings that money alone can’t buy.

A new market study from Bain found that just 2% of customers make up 40% of luxury sales. In other words: A small number of extremely wealthy people are spending a lot of money on fashion. The consulting firm suggests that luxury brands cater to these clients with things like personalized, exclusive products or experiences. A new case study from the Business of Fashion looked at how three brands are ramping up the attention they pay to these top purchasers, known as VICs, or “very important clients.”

For example, Gucci opened its first appointment-only location last year in Los Angeles and runs similar appointment-only floors at its London and Tokyo flagships. Designed by set and production designer Gideon Ponte, the Gucci Salon Melrose is set to look like a mix of a private home and a movie set, according to the company, and some of the brand’s most exclusive items are on display there. Each appointment is customized.

Tiffany & Co. offers its high-end clients the chance to commission bespoke jewelry from its chief artistic officer at its New York flagship, while Mytheresa, a German-based luxury apparel and accessories brand, is running what amounts to an events business for its top clients. Mytheresa offers experiences that can’t be bought, like dinners at designers’ private residences.

Meanwhile, Neiman Marcus is focused on reaching shoppers who spend more than $25,000 a year, according to The Wall Street Journal. The store pulls out all the stops for them. After one Neiman Marcus shopper lost her diamond engagement ring, for example, the retailer paid for first-class flights from San Francisco to New York and a three-night stay at the Baccarat Hotel for her and her husband to have a private shopping appointment at one of its suppliers.

These custom-tailored products and experiences don’t come cheap. They do, however, appear to be paying off. Bain said this month that the overall luxury market saw 8% to 10% growth in 2023 compared with 2022—even though sales of personal luxury goods fell in the Americas—and it projects the luxury market to see modest growth in 2024.