Build your audience on a course community: If you’re just getting started building an audience for yourself and want to leverage communities already actively looking for content you can choose to host and sell your online course on a site like Skillshare or Udemy. These are easy, cost-effective ways to build an audience and test your niche to see if there’s demand for it.
What these opportunities typically turn up to be is a pyramid scheme. You pay a fee to signup. You then receive a flyer saying how great stuffing envelopes is and list of names and addresses to mail said flyer. IF those people pay that signup fee so they can mail that flyer too, you get paid a small referral fee. ONLY if they take the bait do you get paid.
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. 
What’s the catch? None, really. Cash back apps act as affiliates for many online merchants, which means that whenever you make a purchase through one of the apps, they get a small commission — but then, they give you a portion of that commission as “cash back”. For example, if I buy a pair of Nike shoes through the Ebates app (or website) and spend $75, Ebates may get a $10 commission but then they’ll pass $7 back to me. It’s basically a way to get sale prices on stuff that isn’t on sale!