If you love design and you are an artistic person, selling digital products on Etsy could be a great way to earn passive income. Digital products require little maintenance, your customers will simply receive a link to download them (which means you don’t have to worry about shipping and returns handling). All you need to do is spend time upfront to create beautiful artwork! (Easy right?)
Similiar to Adsense, Media.net powers the Yahoo! Bing Network Contextual Ads and is probably the second largest contextual advertising company in the world. I've been running some Media.net ads for a few months and the income was very similiar to adsense. Bear in mind that their approval process is a bit more extensive than Google AdSense. -One has to get a certain number of page views monthly to get an account with them.
Another great way to get started is to identify an area of interest you have. For instance, Robert Duff has been successful in building passive income by selling books on Amazon. Then, go out and start talking to people. Ask them, “What are you struggling with right now? What are your biggest pains? What’s something you wish existed that doesn’t?” That’ll give you some ideas about where to get started.
As we’ll discuss, passive income opportunities are usually limited-time only, and honestly, over half of what you try won’t work. Diversification is your friend. Having many sources of income — at least 7 including your “day job” — is an important hedging strategy. Personally, I have been working at it for a long time, and I’ve had many failures in trying to build my portfolio. I’ve done a few apps for BlackBerry (come on, it was 2009), contemplated writing a book, started a bunch of blogs and forums, and joined countless affiliate programs. Here are the ones that are currently working right now.
If you have specialized knowledge in a certain topic, you can put together an online course to teach others. For example, if you have experience in real estate investing, you can create an online course “Real Estate Investing 101”. The benefit of an online course is that once you create the course material, you can sell it to as many people as you want.