Twitter co-founder, Jack Dorsey listed his first tweet as a unique digital signature on a website for selling tweets as non-fungible tokens (NFTs), according to a Reuters report. Dorsey's first ever tweet 'just setting up my twitter' was posted in March 2006 and has received offers that went as high as US$88,888.88 within minutes of Dorsey tweeting a link to the listing on Valuables by Cent, a tweets marketplace. NFTs are digital files that serve as digital signatures to certify who owns digital media, including photos and videos. A tweet's buyer will get an autographed digital certificate, signed using cryptography, that will include metadata of the original tweet, according to Valuables' website.