Rob Gronkowski made a big splash in April 2021 when the Tampa Bay Buccaneers tight end became the first professional athlete to launch his own non-fungible token (NFT) trading cards. A sports marketing curiosity not that long ago, NFTs are becoming mainstream as creators tap into sports fans’ hunger for novel collectibles related to their favorite athletes and teams. An NFT is a unique digital asset or token that is linked to digital art, music or a collectible. A network of computers records the sale of NFTs on a …