17. Amazon – Have you heard of FBA? It stands for “Fulfilled by Amazon” and it’s getting pretty popular. Basically, you buy products (in bulk is best) and ship them to Amazon for them to store. When your products sell, Amazon packs them up, ships them out and sends you the money (after taking their cut). There are people making a full-time living from FBA, while others just do it for some extra money.
If you’re in the WordPress industry like I am (whether it be design, development, or SEO) I have accumulated quite the list of WordPress affiliate programs. I excluded those I found unsuccessful or pay too little to make a profit from, specifically ThemeForest, Creative Market, and low quality theme stores like Template Monster. Hosting pays well and I wrote a tutorial for SiteGround’s affiliate program and StudioPress themes which are my 2 highest paying affiliates. Those tutorials have tons of screenshots/social proof especially for SiteGround.
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.