If you are knowledgable in affiliate marketing, it can be very profitable. Credit: Shutterstock

39. Affiliate Marketer

Affiliate marketing is when a business pays a commission when someone else helps them make a sale. For example, if a blogger recommends a new shampoo, and someone buys it, they can receive a small commission on that sale. There are some online blogs and websites, as well as YouTubers that make their entire income off of affiliate marketing.