Ticket exchange site since 2000

STUBHUB

Think of where you might resell a concert pass you can’t use—it’s been around for decades.

This clue points to StubHub, a well-known online marketplace for buying and reselling tickets to events like concerts and sports games. The phrase "since 2000" hints at its founding year, confirming it’s the right fit. "Ticket exchange site" directly describes what StubHub does—connecting sellers with buyers for secondhand tickets.