Passive income is defined as income-generating activity that is independent or loosely dependent on time commitment. Just so we’re on the same page, here, there’s no such thing as making money without creating value (I wish), and creating value takes time and effort. So, you are technically transacting time for money, in a way. But passive income is where we separate or at least alienate the proportional relationship between time spent and money made. It’s where there is no longer a fixed ratio, and if there is, it’s not a 1:1 ratio, but more like a 10 or 20:1 ratio of man-hours-worth-of-time to actual time. As another side note, knowing how much your time is worth both to you and on the open market is a valuable piece of information for guaging how effective your passive income activities need to be.
Courses are similar to guides but they’re easier to produce for some subjects, especially tech subjects. If you’ve got a computer, a decent microphone and some screen recording software, it’s pretty easy to create high quality courses. You can sell your course through your own site or you can use a marketplace like Udemy to do all the heavy lifting. 
It’s not just the little guys like me who are being squeezed by the constant updates. Even YouTube’s top creators have expressed frustration with changes to the YouTube monetization platform. It’s constantly changing and evolving, so you must be willing to adapt. Plus, it helps having a blog so you’re not relying on a single platform or your income.
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.