There have been a number of websites with a fee to create an account, to prevent spam. Metafilter, Something Awful, Bitcoin Wiki previously. There are also sit

There have been a number of websites with a fee to create an account, to prevent spam. Metafilter, Something Awful, Bitcoin Wiki previously. There are also sites meant to be exclusive with fees $1000 and up https://www.theverge.com/2017/4/26/15407144/exclusive-social-media-the-league-best-of-all-worlds-rich-kids https://www.theverge.com/2017/4/26/15407144/exclusive-social... I've also heard proposals of email readers charging fees that senders have to pay, to stop spammers from being able to send them anything. Sometimes it's a computation fee instead of a monetary fee, a proof of work to rate limit spammers.