See https://www.lesswrong.com/posts/9cvK8QX9ZRBxmEfcz/consider-paying-for-literature-or-book-reviews-using

In theory, writers could kickstart posts using dominant assurance contracts. An example (this is a real offer): If you send $20 to arjun.panickssery at Gmail via PayPal by noon New York time on January 21st, I'll send you back $25 if fewer than 10 people sent me money. If 10 or more people send me money, I'll post a review of Steven Pinker's The Sense of Style: The Thinking Person's Guide to Writing in the 21st Century by the end of the month. I'm not sure whether I'm just giving away free money right now.