Mechanical Turk: Amazon's Mechanical Turk is a resource for doing human-intelligence tasks, or as the site commonly refers to them, HITs. You get paid a very small fee for any given HIT and you'll need a good deal of volume to make a substantial amount of money. But it is a resource you can use in your spare time to generate a small income online.
Earn cash back for shopping. Earning cash back on your purchases is a smart idea, and credit card rewards aren’t the only good cash-back strategy out there. With sites like ShopAtHome.com, eBates.com, and TopCashBack.com, you can earn up to 10% cash back on purchases made with approved merchants. Many frequent shoppers also love the Ibotta app, which lets you earn cash-back on every purchase.
eBay is the most popular global auction site around and is a great place to sell items you no longer want. If you are looking to earn some extra cash, start out by looking around your house for things you no longer want; list them on eBay and watch as customers bid on them. You can also purchase clearance sale items and thrift store finds and make a couple dollars profit by listing them as well. The key to selling on eBay is to do your research and find out what the hot items are.