You can sell your ebooks through Amazon's Kindle program or Apple's iTunes Connect, which gives you access to a large majority of the digital-book reading market and the barriers for entry are incredibly low. You don't need to invest lots of money to make this happen, but you do need to invest lots of time, not only in writing the ebooks, but in marketing them as well.
First off, I’m a blogger so it seems wrong not to mention it, but more importantly, it’s a legitimate way to make money. It’s quite possibly the least straight-forward way on this list, but it’s very doable and it’s also quite possibly the funnest way on this list. I love blogging and I know hundreds of bloggers who feel the same. So let’s talk about making money blogging and what it really means.
Rather than making money through subscriptions, YouTube channels are based on a traditional advertising system. Meaning the more viewers you get, the more you make. Once you’re approved for the YouTube Partner Program and can start including ads on your videos, with every 1,000 views, you will make approximately $2-$4. Which might not seem like a lot, but if you have 100 videos with 5,000 views a month each, that would be $1,000–$2,000 already. Just imagine if your videos start hitting millions of views!