But don't make the mistake of thinking this will be a passive source of income—you're on call whenever you have a guest and you'll always need to keep the place clean for incoming visitors. On top of just renting on Airbnb, consider offering your guests paid add-ons, like Lauren Gheysens', Royal Day Out in London, England—where she gives visitors a local's only tour of the city, complete with bespoke 18th century costumes.
Better yet, you can even upload your own book to one of the world’s largest book sellers: Amazon. With Amazon self-publishing, you set the price, retain the rights to your book, and get access to Amazon’s massive audience. For every sale, you keep 70% with Amazon taking the remainder as a fee. If you want to get started, check out Leslie Samuel's great guide to selling eBooks online or follow Tara Gentile on CreativeLive as she shows you how to use your existing body of work to write an eBook within the next week. Who knows, you might just write one of the best business books of this year!