Good list. Some definitely good examples, if people really want to try. I think “interview other people and sell the interviews” will work the best. Or just build a website and post those interviews. I have managed a few websites where we interviewed people and those get a lot of visits from Google searches. For anyone out there willing to interview people I would recommend it, it will make you money.
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!