Another popular site to earn money doing gigs is Amazon's Mechanical Turk. You get paid a very small amount per gig (sometimes as low as $0.05) but you can do these tasks very quickly. For example, you could be asked to identify a picture or type certain text. When I was in college, I used to do these gigs in class and earn money while taking notes.
The money is most certainly in the list. If you're at all interested in online marketing, setup email software and create a lead magnet that you can use in your sales funnel. Then, build up that list. It's often said that you can expect to earn about $1 per subscriber per month. If you have a list of 10,000 subscribers, that means you can earn roughly around $10,000 per month. You will need to deliver value and not pitch them on every email, but it is a very achievable goal in a short period.
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!
Using a food delivery service can’t necessarily earn you money, but it can help you save you money if you constantly find yourself throwing out half the food you buy. Food delivery services send a box of food every week with new, sometimes unique vegetables, meat, fruit, and so on. If you don’t have time to shop and want simple meal-prep that leads to a good meal, a food subscription service may be perfect for you.