If you have a background in a specific field, you may find there is a demand for writing industry papers in your area of expertise. For example, there are often adverts for doctors, lawyers, nutritionists, and business experts from particular niches, to write white papers on different subject areas. These are well paid jobs that you will need to stake your reputation on, but that can often be worked on from the comfort of your own home.
And this is really why a complete profit funnel is so important because it typically augments the value per visitor. By building a list, providing value and offering related products I might be able to earn 50 cents per visitor, but by simply having a site that redirects visitors to the sales page (without collecting names and email addresses) then I may only get 5 cents per visitor. Trying to find paid traffic sources for less than 5 cents per visitor is hard, if not impossible, so you have to rely on free traffic sources and that really limits your rate of growth.
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 Upwork, which makes this a high-demand opportunity to make money online.
The peer-to-peer concept is coming to virtually every corner of human existence. That includes the hospitality industry. Through AirBnB you can actually rent out your house for various lengths of time for a predetermined fee. That gives you an extra income on your house and gives the visitor the benefit of having an entire house, rather than being crammed into a single hotel room.