If you're serious about making money online, start a blog. Blogging is one of the easiest and most sustainable income sources. As long as the blog is setup the right way, in the right niche, with the right content targeted at the right audience, and the offer is complementary to the content, you could make a tremendous amount of passive income from a blog.
Market your course: The beauty of using a course to make money online is that you can continue to sell it for as long as you’d like. Look for niche communities on Facebook, LinkedIn, or Reddit that might benefit from your content. Guest post on relevant blogs and sites. Look for anywhere you might be able to get in front of the right people. With just a few hours a month you can continue to generate sales.
The difference between Amazon and EBay is that EBay (though still filled with new items) is seen as a used marketplace between individual parties, whereas Amazon (which is filled with offers for new and used merchandise from the 3rd parties) is viewed as a Wal-Mart-type superstore. As a consumer, this difference leads me to use Amazon, so it only makes sense to target on my own demographic.
Sign up for a reputable affiliate network: Aside from Amazon, there are dozens of large reputable affiliate networks, such as Share-A-Sale, Clickbank, and Skimlinks, that specialize in connecting you with merchants who are looking for affiliates to sell their products. They charge relatively low commission fees for the privilege of connecting you with merchants, and the merchants on these sites tend to offer much higher commission percentages or set dollar amount payouts.
If you’ve got expertise in a certain area, package up your knowledge into an online course and sell it. This has become a very popular business model for online entrepreneurs over the past several years. The two big websites that are used to sell online courses are Udemy and Teachable. Check out this awesome article by Regina on How to Create an Online Course that Sells.
Unless you're a freegan and have found a way to live entirely off the grid, you probably need some sort of steady income in order to survive. The traditional way to earn money, of course, is by having a job. You work for a company or start your own, and the work you do earns you money, which you spend on things like a mortgage, rent, food, clothing, utilities and entertainment.
Robo-advisors are diversified investment accounts that are automatically managed by a computer algorithm (as opposed to a human money manager). If you want to invest, but don’t have the money, or don’t want to invest with a money manager, robo-advisors are for you! Robo-advisors make investing easier—and cheaper—so they’re perfect for new investors.