I personally have enjoyed working a direct sales/home based business on the side. I found a good, legitimate company with very low upfront costs/overhead. It has been a great experience. Just be sure that the company offers training and some sort of simple, step-by-step system and it helps if they are in the DSA Top 100– instantly proves their legitimacy!
Are you a professional in a field that can help answer questions for people looking for your expertise? Websites like JustAnswer and LivePerson match you up with people looking for answers to technical or professional questions. You can make money online by simply answering these questions and providing the right information to people based on their individualistic circumstances.
Great list! I’ve used Poshmark to sell clothes/accessories. You take up to 4 photos, add a description, and set a size, color, and brand. I’ve sold 3 items so far (two dresses and a pair of shoes) and it’s easy. The buyer can purchase at listing price or make you an offer, to which you can counter-offer. At all times, you can see what your profit will be from your listed price. Once the transaction is accepted, you are emailed a prepaid shipping label to print. You package your item up in a brown box and ship, and when the seller receives it your funds are released. You can cash out as a direct deposit to a bank account at any time or use the funds to shop. I’ve also purchased a pair of jeans on the site and they arrived as expected. For like-new and designer labels it’s a great way to clear your closet and make a little cash all at once.
Decluttr lets you sell everything from books to CDS to DVDs to electronics and even LEGO! It's my best recommendation for decluttering (hence the name!) by selling stuff you no longer want or need. With books, you just enter in the barcode or ISBN and they'll give you a value. It takes minutes to find out how much your stuff is worth and you don't have to register or anything to price things.
If you have a propensity for writing and you can slay with your prose, consider writing an ebook. While the market has certainly become saturated as of late, books that help teach people about a technical topic still sell extremely well. This is a great source of passive income but does require a large amount of effort at the outset before any money is generated.