Let’s say I’m an Amazon affiliate for camping gear, and I want to write an exhaustive, in-depth blog post and review of the “50 Best Hiking Backpacks for Adventuring Outdoors.” By running a quick Keyword Planner check on the organic search volume I can see that there’s around 5,500 monthly searches for the keyword ‘hiking backpacks’ alone. I'll then start with putting together a blog post outline to highlight my unique angle and make sure I'm doing the best possible job of answering reader questions.

Starting a podcast, like making a YouTube channel or blog, comes down to telling interesting stories and building an engaged audience. I’m probably sounding like a broken record by now, but you need a niche that you’re interested in and there’s already a demand for. Come up with a list of topics you’d like to talk about and then search iTunes charts, Google Trends and other podcast research sites like cast.market to see what’s currently out there and popular.
Considering that you have a finite amount of time, passive income should make up a large part of your work. If you're serious about generating any semblance of income online, then passive income should be one of your sole goals and ambitions. Why? Wouldn't you prefer to do the work one time and get paid repeatedly as opposed to relying on your time to generate that income? Invest the time at the front-end so that you can reap the benefits on the back-end. This means putting in a bit of sweat equity and not getting paid today. Rather, you'll get paid somewhere down the road. And you'll continue getting paid whether you keep building that passive income stream or you stop. 
Join a startup accelerator: Another great option is to apply to a startup accelerator like Y Combinator, 500 startups, or TechStars, where a group of investors will help coach you, connect you with potential partners, and provide startup cash in return for a small stake in your company. The competition is tough to get into these, so don’t rely on them as your only path forward.
As long as there is still the written word, there will always be editors. Freelance editing and proofreading not only pays a decent hourly wage, it also gives you the chance to read about potentially interesting topics too. What's more, pursuing freelance writing & editing as a business idea can afford you a lifestyle that lets you travel the world as a digital nomad. You can find lots of job postings from companies and individuals in need of writing, proofreading, and editing services on Contena, which makes this a high-demand opportunity to make money online.
Once you have that problem or need nailed, the next step is to validate that idea and make sure you’ve actually got customers who will pay for it. This means building a minimum viable product, getting objective feedback from real customers, incorporating updates, testing the market for demand, and getting pricing feedback to ensure there’s enough of a margin between your costs and what consumers are willing to pay.
Please note that some of the links below are affiliate links and at no additional cost to you, I will earn a commission. Know that I only recommend products, tools and learning resources I've personally used and believe are genuinely helpful, not because of the small commissions I make if you decide to purchase them. Most of all, I would never advocate for buying something that you can't afford or that you're not yet ready to implement.
_{29. Videos – This could be an entire section on it’s own. Many people have made money by creating YouTube videos. Evan of EvanTube is a kid and he has made millions by creating reviews of products that other kids his age would use. It’s not easy to get views into the millions, but once you do, you’ll start seeing some cash come in. Many bloggers have completely turned to videos to get their point across by starting a video blog.
Whether you have a website or are still dreaming up ideas for a blog, you can also look into affiliate marketing. With affiliate marketing, you partner with brands and businesses within the content of your website. If you mention a product or service, you link to that produce or service using a unique affiliate code you received when you signed up for that particular affiliate program. From there, you’ll make money any time someone buys a product or service through your link.}

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.

You can sell your ebooks through Amazon's Kindle program or Apple's iTunes Connect, which gives you access to a large majority of the digital-book reading market and the barriers for entry are incredibly low. You don't need to invest lots of money to make this happen, but you do need to invest lots of time, not only in writing the ebooks, but in marketing them as well.