Passive income can be defined as a revenue stream that repeatedly comes in after your hard work has been done: like royalties on a bettles' song, it goes on forever. At Ghost Writers you can sell textbook summaries, questions, essays, class notes, case assignments and other types of study resources that you've already created in the past. After uploading your content, no additional work is required to sell. Ghost Writers markets your documents for you, so while you’re busy doing other stuff you’ll automatically get paid every time a document is downloaded! On average, a single document can provide you with earnings up to $100 in its first month!