You can pay for new book, interesting artwork, new font.
At Paywithatweet.com you can learn more. And you can sell something "for a tweet".
Actually, all our Twitter accounts have their value (which you have probably checked already at Tweetvalue.com ), and it means that we bring our value to those things we are tweeting everyday.
A clever young men came up with an idea of the Stock Exchange of Twitter accounts,which now exists in Russian cyberspace. There you can buy shares of a particular person / company / account, as well as to sell, earning this money. Check it --> Twistosk.
Which will be the next innovative step in social media-money relationship?