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.
There are also shopping apps like ibotta, MobiSave, and checkout 21 that give you money back for shopping. And the Walmart app has a savings catcher feature where you take a picture of the barcode or upc at the bottom of your receipt and they search all surrounding store and if a lower price is found they give you the difference back. I have made about 50 bucks total from this app and 20-30 from things like ibotta.
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.