Trade-In (Resale) Marketplaces. There are plenty of other places to sell your stuff online, especially if it’s electronic. Popular and reputable online resale marketplaces include SellCell, Gazelle, and MaxBack. Major retailers such as Best Buy have extensive trade-in programs as well, as do national carriers such as Verizon and AT&T. Decluttr, a hybrid option, cuts out the middleman and claims to deliver better value for unwanted tech items.
Prior to that group, they had an online community for teachers looking for lesson plans. That probably sounds pretty random, but it's crazy the type of communities you can build and rally people around. If it's something that you're passionate about yourself and you want to connect with others that have that same passion, then an online community is something you should definitely consider.
Teaching and tutoring English as a second language is a great way to make money online, not to mention open some doors for you to travel the world if you’d like. While full ESL (English as a Second Language) accreditation is recommended, as long as you’re a native speaker and have the ability to teach, there are people in countries such as Hong Kong or the UAE who are willing to pay upwards of $25/hr for you to tutor them English via Skype. Check out Indeed, Learn4Good and Remote.co for remote english tutoring jobs or sign up on a specialized site like VerbalPlanet or Chegg Tutors.
Ebay is a bellwether. It's been around since nearly the start of the online boom. But, like any other platform, success can seem fleeting if you don't know what you're doing. Selling items on eBay, professionally that is, can be an art form. Getting people interested in your auctions isn't always easy, especially when there's hefty competition and low demand for what you're selling.
Amazon. Many people don’t realize that Amazon is a haven for third-party sellers cleaning out their attics and garages. If you plan to sell more than 40 items per month on Amazon, consider registering as a professional seller. You’ll need to pay a roughly $40 monthly subscription fee, a referral fee that usually ranges from 6% to 20%, and a per-item closing cost for media items. You won’t pay the per-item selling fee, however. Alternatively, you can register as an individual seller. The fee schedule is the same as for professionals, except you do have to pay the selling fee and don’t have to pay the subscription fee.
…Marketing an eBook is definitely the hardest part. Ebooks have exploded in popularity and the market is unfortunately saturated with crap from people who thought they could write a quick eBook, put it on an affiliate network, and make millions. However, if you CAN find a good way to market (or possibly have others market by having it listed on affiliate networks) then an eBook can be a great way to make some residual income.
Amazon makes it fairly easy to list and sell old books, games and devices on its marketplace. You can make more than just a few bucks If you have pricey textbooks from college. Be sure the books are in good condition. You'll get negative reviews if you attempt to sell books that are falling apart or games that are scratched up. Remember, be upfront about any defects, no matter how small they might be and no matter how few people might readily notice it.