If writing books interests you, an option you have is to self-publish eBooks and paperbacks with Kindle Direct Publishing, and reach millions of readers on Amazon. Publishing takes less than 5 minutes and your book appears on Kindle stores worldwide within 24-48 hours. One can earn up to 70 percent royalty on sales to customers in the US, Canada, UK, Germany, India, France, Italy, Spain, Japan, Brazil, Mexico, Australia, and so on. One can keep control of one's rights and set their own list prices and also make changes to one's books at any time. BooksFundr and Pblishing.com are two other places to get your book published and earn money.
Those who love teaching but would prefer to make passive income could consider teaching online courses. With online courses, you can teach topics that go beyond what a tutoring gig for students would teach. If you’re great at building stable relationships, you might create a relationships course. If you’re an ecommerce expert, you might teach a course about dropshipping. There’s no limit to what you can teach. You can also niche down within an industry to teach courses about specific subtopics. For example, instead of teaching public relations you might teach a course about growing your blog traffic.
The concept of data mining and profiting off that data mining isn't anything new. And while some companies engage in some rather disreputable practices to do this, Global Test Market seems to be doing just fine with the whole “consent to disclose” thing. More importantly, in some cases this may help you as some companies will offer to do more specialized product testing once they've identified you as their target demographic.
The interesting thing about sites like Bubblews is that anyone can join and publish short articles that earn small bits of money based on the number of views, comments, and other activity they receive. I’m a living witness that I’ve made $25 thus far from the site – albeit very slowly – and Michael Cimicata has apparently made at least $42.45 from the site as well.
Research other listings in your city on AirBnB and see what the going rate is for a place like yours. You could also just rent out a private room as well or even a bed in a shared room. In fact, that's how AirBnB got its start. However, you might find it hard in the beginning without reviews, but as long as you take really good care of your guests and provide a lot of value, the reviews will eventually come rolling in.