Multi-vendor marketplaces, like ThemeForest, can be very successful. Chose a niche and create a vendor website for it. Your marketplace could be anything, from a platform for local artists to sell their work on, to an online digital product store. Once set up, invite people in that industry to sell their products on your site. You take a percentage of their profits when items sell.
There’s an excellent chance that you have one or several musical instruments sitting in storage that haven’t been used in years. Perhaps it’s a leftover from when you were in school, or even from your days playing in a band. Whatever the reason that you have it, it’s probably worth money if you can sell it. Brand-new instruments are ridiculously expensive, so people often look to buy used equipment instead, particularly if they are novices.
Today, if you're at all serious about succeeding in any endeavor, whether online or offline, you have to deliver enormous amounts of value. Yes, you have to do the most amount of work for the least initial return. This is especially true online. Why? Because it takes time to build authority and create an audience, two primary ingredients necessary to succeed in the wonderful world of commerce on the web.
If you’ve got a way with words and expertise in a niche, there are plenty of sites that will pay for articles and content you write. Think of the sites you read regularly. What can you contribute to them that would be interesting? Research your niche and then look for ways to pitch articles. Many sites will simply have a submission or contact link in the footer. To get started, check out my full guide to becoming a freelance writer on the side and then submit your articles to places like Listverse, TopTenz, A List Apart, International Living, FundsforWriters, and Textbroker.
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.
How much will you make? I think my best month with Google AdSense was almost $5,000 over the last ten years. That amazing month blew my mind since it was actually near the beginning of my blogging journey. When you go from making zero to $5,000 in a month, that will rock your world. For me, it also got me even more excited because I knew there were other ways to monetize.