A study conducted by scientists at the Queen Mary University of London involved the analysis of 2.6 million posts on the well-known social networking site, Nextdoor. Surprisingly, they were able to predict a user’s income accurately, using only the content of their posts.
Nextdoor is sort of cheating for this, tbh. Not quite as much as LinkedIn would be, but not far off.
Would be more impressive if it used Twitter or Reddit. Although even then I’d bet that enough people outright post their salary to make it difficult to see how accurate it actually is