According to research conducted by thredUp, the second-hand clothing market will grow to nearly 1.5x the size of fast fashion by 2028.

"The last few years of growth in the resale market have been driven by the early adopters (the same ones who first adopted Airbnb or Lyft or DoorDash), but now the skeptics are starting to come around," James Reinhart, Co-Founder & CEO of thredUP said. "We’re seeing first-time thrifters coming to platforms like ours in droves. Not surprisingly, the younger generations are leading this charge, with millennials and Gen Z adopting secondhand 2.5x faster than other age groups."

The thredUp report says that in 2028, the second-hand market will be worth US$64 billion, in comparison to US$44 billion for fast fashion. As of 2018, fast fashion was worth US$35 billion and second-hand US$24 billion.

"The retail sector needs to find ways to embrace, acquire, or partner with second-hand shop business models because customer adoption is likely to continue," broker-dealer business Cowen and Company said. "Customers of the future will look for ways to recycle, resell or upcycle, and will be drawn to the incredible value of buying secondhand. We believe that brands will need to partner with resale sites and support the circular economy."

Even traditional retailers are starting to embrace secondhand. For example, Airbnb is building homes that are designed to be shared, not owned, and IKEA has announced plans to offer furniture rentals.

"The resale customer is no longer somebody else’s customer, they are everybody’s customer," Reinhart added. "Mass market or luxury, if people can find a high-quality product for much less, they’ll choose used. As the line between new and used apparel blurs for consumers, a powerful transformation in retail will unfold