Earning by comments will require you to have your own Blogs and Websites. You will then share these dedicated domains (Owned by You) in the comment window. If an option to add your URL or website is not available, then you do not include links. You contact the site support first and get permission to share your URL. Oh, and NEVER share affiliate links in comments.
You could also opt to use existing websites for making money. These include both active income and passive income methods. For example, you could sell some used items or invest in creating some digital designs that then can be sold on merchandise. Again, devote a sizable portion of your time to passive income so that you can slowly build up earnings that will arrive on autopilot without any extra added effort. 
One of the most underrated freelancing sites ever. The site started as a place where you could get paid to do short tasks for just five bucks. Over the years, it has slowly morphed into one of the biggest gig/freelancing sites where you can now charge any amount to do all kinds of stuff for other peoples. Anything from serious stuff like copywriting, translation, voice over social media management to silly stuff like prank calls and everything in between.
^{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.}
_{Job well done, Satrap. The first thing I look for in a site like this are signs that the author is being paid to hype the companies. It’s very tough to find good information that isn’t stricken with bias. There were a couple of times during the article where I actually got excited thinking, ‘Hey, I could do that. I’d actually LOVE to do that.” That being said, I can’t help noticing that you refer to all of it as “extra” or “supplemental”income. Are you saying that with all of these options, sticking to one’s regular “day job” is required? In your experience, if someone really commits to doing this, is it possible to earn a decent living? Cubicles suck.
While it often takes a significant amount of time and hard work to build up your affiliate income, if you have the ability to regularly publish high quality content that drives in targeted traffic to your website, this online revenue source can become quite substantial. Follow along with my experiment growing two completely new blogs—one finance blog MoneyTalk and one called SmartWP about WordPress, into additional revenue streams for my business.}

My next self-funded business hit $160,000 in revenue in its first year alone. After that first taste of self-made success, I’ve gone on to sign consulting contracts worth tens of thousands of dollars with startups like LinkedIn and Google, launch profitable online courses, and grow my blog to over 400,000 monthly readers and $50,000/mo in side income.

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.
And while it will take time to build up a big-enough audience to attract advertisers and other ways to make extra income from your podcast, the opportunity is there. John Lee Dumas interviews entrepreneurs seven days a week for his podcast Entrepreneur on Fire and now makes more than $200,000 a month from it. In fact, John publishes all his income online and showed that he’s made almost $13 million since launching in 2012.
The first follows the startup path we outlined above: You have a disruptive idea for an app or piece of software, you validate the idea with real customers, and then raise money to hire developers or a development studio to build, launch, and scale your software. If you’ve done everything right, your software will be accepted to the Apple and Google Stores and you’ll make money every time someone downloads it or pays for a premium feature.
Has anyone ever told you you have a voice for radio? Are you great at creating original characters with just your voice? There are tons of people looking to pay for quality voice overs for their corporate videos, animation series, or educational videos. Check out Fiverr and UpWork or create a profile on a specialized site like Voices.com or The Voice Realm to get started making money online doing voice overs.