LAST JUNE. BRAD PITT, the actor and family man, was spotted at Design Miami's Swiss satellite during Art Basel. Pitt had barely left the building when press releases announcing details of his purchases hit in-boxes around the world. The celebrity obsessed Us Weekly magazine was soon reporting that the superstar had picked up a pair of bronze Poly chairs by the up-and-coming British designer Max Lamb for $25,000 each at the booth of New York's Johnson Trading Gallery and, appropriately, the foam and fiberglass Family Lamp of Atelier Van Lieshout, for $56,000 from London's Carpenters Workshop Gallery. Bloomberg, Page Six and even Arianna Huffington's politics-and-pop-culture blog announced that Pitt had spent $293,000 on a limited-edition marble Cinderella Table by the Dutch designer Jeroen Verhoeven, also from the Carpenters gallery. The spree continued at the booth of the New York gallery Sebastian + Barquet where he bought a pair of Ron Arad chairs; he then ordered a custom aluminum-thread rug by the Colombian designer Jorge Lizarazo, at $175 per square foot, from the New York dealer Cristina Grajales. By the time Pitt hit Kenny Schacter's booth he might have begun suffering from shopping fatigue, because he didn't finalize the deal on the $300,000 gold fiberglass sofa by Zaha Hadid he had admired.

The screen star, it seems, has cultivated a sure and sophisticated eye: Pitt made the rounds unaccompanied by an art adviser, at least in Basel. What's more impressive than his connoisseurship, however, is that reports in Us Weekly about his couple of hours at the fair did more to put design in the minds of mainstream America than any Marc Newson extravaganza at Gagosian or Ron Arad record-setting auction price.

Nevertheless, the collision of design and celebrity predates Brad in Basel. On opening night of the first Design Miami fair, in 2005, the buzz among the hip and beautiful poolside at the Raleigh hotel was about who'd just paid $350,000 for a midcentury wood screen. The buyer's identity was soon confirmed: The fashion designer Donna Karan had purchased the hand-carved, one-of-a-kind piece by the Franco Hungarian designer Pierre Szekely at the booth of the New York dealer Magen H Gallery before the fair had officially kicked off. Within days even the New York Times was reporting on Karan's acquisition. The fair, then called design.O5 Miami, was one of the first to capitalize on the still-hot (for now) market for design art, and Karan was one of the first bold-face names attached to it. Her fame raised interest in design objects along with their prices, no doubt. Ambra Medda, the founder of Design Miami, proclaimed that "designers are the new rock stars."

Since then, actual rock stars and other celebrities have been hitting fairs, auctions and galleries to scoop up contemporary design items and vintage 20th-century furniture. Some have even emerged as serious collectors. The rocker Lenny Kravitz allied with the Manhattan dealer Todd Merrill to build a notable collection of American furniture by such names as Karl Springer, Willy Rizzo and Paul Evans, whose 1960s and 70s pieces strike a sympathetic chord with Kravitz's sexy glam-rock style. (A small article on Kravitz's collecting in the Financial Times last summer garnered calls to Merrill from potential clients from across the globe.)

The rapper Kanye West, who blogs on design, has furnished his L.A. home with works by the Campana brothers and Ingo Maurer. For his new Manhattan apartment, designed by the noted minimalist Claudio Silvestrin, West has purchased some of Maarten Baas's charred furniture and commissioned a chandelier by his designer pal Yves Béhar.

The celebrity branding of design was inevitable. The public looks to the rich and famous for guidance on what to wear, where to go and how to live-even following their lead on real estate. Remember when Tom Ford and the actress Kelly Lynch started the craze for Richard Neutra houses in the late 1990s?

There is, of course, a big difference between the designer handbag spied on a starlet's arm and a $300,000 sofa. Like a Neutra house, such a prize is not within every stargazer's grasp, aesthetically or financially. But as surely as celebrity endorsements are good for the bottom lines of Gucci and Prada, Brad Pitt's latest obsession is good for furniture designers, dealers and other collectors - a star turn for the design world.