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!
You may decide to create free videos as extra content for your blog, and not sell them at all. If this is the case then you can still make money from these videos by selling advertising space on them (in the same way as discussed for monetizing podcasts). Once you have high volumes of traffic visiting your blog, and watching your videos, you can charge businesses to advertise at the beginning of your videos. Use website’s like Izea to help you connect with companies willing to pay to advertise on your blog.
Online business is how I’ve made a living since 2003 and what has helped me retire early. I make over $20,000 a month through my blog. You can create your own blog here with my easy 15-minute step-by-step tutorial. You can start a blog for as little as $2.95 a month (less than a cup of coffee!). Create a blog and leverage it into affiliate sales or product endorsement deals. Consider topics like:
Dating sites and apps are extremely popular and have become more and more niche as the industry develops. They can also be very profitable, as there are many ways to monetize them. You can charge a joining fee, provide premium subscriptions, or make money from advertising on your site. White Label Dating provides a pre-built dating platform for your project. You simply choose the niche and branding for your new dating site. Once your website goes live, you just need to promote it, manage the users, and collect the earnings.
Another site worth checking out is BookScouter, which will check the selling price on 55 different vendors. The list will include the offer price, how they pay (Paypal, check, etc.) as well as whether they pay for shipping and under what terms. If you have a lot of books to sell, they can search up to 3000 ISBNs in a single request if you upgrade to BookScouter Pro. There is also historical prices too in case you want to review trends.
Find a profitable niche. Starting with your interests, write down as many niche ideas as you can. Think about topics people might search online. Ideas include passions (like surfing or body building), fears (like spiders or speaking in front of crowds) and problems (like getting out of debt). Do keyword research to see it others are interested in the topic. Find out if a domain name is available that matches the keyword 100 percent. 
If you’re looking for inspiration, my friend Michelle Schroeder-Gardner of the website Making Sense of Sense has become the expert on all things affiliate marketing. Michelle earns more than $100,000 per month from her blog and the bulk of her income comes from affiliate sales. Michelle has had so much success with affiliate marketing that she even has her own course called Making Sense of Affiliate Marketing.