19. eBay – Of course you can’t read an article about making money online that doesn’t mention eBay. You can start an eBay store and get serious about it or you can just sell some stuff to declutter your home. Either way, I’ve made my fair share from selling on eBay and it’s still a popular way to earn money. If you decide to start an actual eBay store, you’ll want to find a drop-ship business like Doba that will store and ship items straight to your customers so you don’t have to deal with an inventory.
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. 
Set reasonable expectations for earnings. You've only invested $20. You're going to make 5 percent on most products. That means that you need to sell $400 worth of stuff to make back your investment. You get credit for purchases customers make while at Amazon besides just the product you linked to, so it's not as hard as it may sound. It won't make you rich, but it's not hard to be profitable, and the income builds over time.
Amazon customers are loyal. Beyond that, Amazon customers--especially Amazon Prime members--are more than happy to convert. According to a 2015 report, Prime members are said to convert at a rate 22 times greater than customers that shop with other top online retailers. So, if you can tap into that audience and appeal to their willingness to spend money with Amazon, you should see a good return on your decision to join the program.
28. Subscription – If you think of something valuable (newsletter, online magazine, etc.) that you can consistently offer on a certain basis (weekly, monthly, etc.), you may want to offer a subscription service. This could be a fee charged each time your product is sent out or on a monthly basis. Either way, this has to be something that your customers can only get by subscribing to your website.