Twitter now has a paid subscription service called Twitter Blue. It will cost $2.99 per month but Twitter has not confirmed what it will do exactly.
One user confirmed that she had been given an early signup and it seems that the paid feature allows users to Undo Tweets. Unpaid users can currently do that by deleting Tweets. It also allows users to create collections and folders of Tweets so that you can refer back to them later like emails.
Twitter has also been working on a “tip jar” feature that lets people give money to other users. This is not made to split the restaurant bill with friends like other payment services. It is meant to support the voices and brands of “creators” such as journalists, experts and other non-profits. Most major news organizations will probably disallow it for their reporters.