Jack Dorsey, co-founder of Twitter, has put his first tweet up for auction, with bids exceeding $2 million.
The message reads, "Just setting up my twttr," and was sent from Mr Dorsey's account in March 2006.
It will be sold as a non-fungible token (NFT), which is a one-of-a-kind digital certificate that identifies who owns a photo, video, or other piece of online content, reports the BBC.
However, even after it has been auctioned off, the post will remain publicly accessible on Twitter.
Dorsey will digitally sign and verify the certificate, as well as the metadata of the original tweet, for the buyer. The information will be included in the data.
The tweet was classified for sale on 'Valuables by Cent,' a three-month-old marketplace for tweets.
The platform's creators equate the purchase of a tweet to that of a more conventional autograph or piece of memorabilia in a blog post on the web.
"Owning any digital content can be a financial investment," it says. "[It can] hold sentimental value. Like an autograph on a baseball card, the NFT itself is the creator's autograph on the content, making it scarce, unique, and valuable."
Old offers for Mr Dorsey's tweet suggest that it was first put up for sale in December, but the listing gained more attention after he tweeted a link to it on Friday. That tweet has since been shared thousands of times.
Within minutes of the tweet being posted, bids reached more than $88,000.
But they skyrocketed on Saturday, with a bid of $1.5m being usurped by a $2m offer at around 15:30 GMT.
According to Valuables by Cent's terms, 95% of a tweet's sale will go to the original creator with the remainder going to the website.