At her vintage store in Santa Cruz, Calif., Mely Olmeda sells a range of clothing, much of it from the early aughts, including sheer tops, low-rise denim flares and anything with lace or loud prints. She also rents rack space to other vendors, which helps pay the rent and other overhead.

“It’s a foolproof setup,” said Ms. Olmeda, who started Virgo Santa Cruz in 2022 and has since doubled the size of her store to 4,000 square feet.

While thrift stores have always been around, the vintage and resale business has boomed — and shifted — in recent years for independent sellers, like Ms. Olmeda, who use creative sharing models. And retail giants like Banana Republic, Madewell and H&M, veteran resellers like REI and Goodwill and property developers are getting into the resale game.

Today, there are over 25,000 resale stores in the United States, and secondhand apparel sales increased about 11 percent in 2023 from the year before, according to statistics compiled by Capital One. In 2023, apparel resale in the United States grew seven times the rate of the broader retail industry, and the used clothing market reached $43 billion, up from about $23 billion in 2018, according to a recent report from ThredUp, an online consignment platform that has worked with big retailers like Lululemon, J. Crew and Abercrombie & Fitch to resell their used clothing.

A varied industry, secondhand clothing stores consist of national chains, small businesses and nonprofits across a range of price points and styles. And while many shoppers like to get their retail therapy fix online on sites like the RealReal and Etsy’s Depop, people looking for the best deals in used goods or a rare vintage item often prefer to see, feel or try on the pieces in person. That makes brick-and-mortar stores essential to the resale business model, vendors and industry experts say.