You don't have to be a professional photographer to sell your photos for money. People are constantly in need of high-quality, unique stock photography for websites, presentations, brochures, and so on, and are willing to pay for the right image. People generally search for images on stock photography sites like ShutterStock, Dreamstime, and iStockphoto by keywords, not by photographer name, so you have the same chance as anyone else of having your image selected. Just be careful not to post images of trademarked brands, copyrighted art, or people's faces that are readily identifiable unless you have a model release.
As someone who's been immersed in a number of online industries for quite some time, I know a thing or two about what it takes to succeed in this arena. However, just like you, I started at ground zero with little knowledge, but a great deal of passion. What I learned along the way were some invaluable lessons from failure that hurt at the time, but helped immensely in the grand scheme of things.
If you start getting too big for EBay or decide you want to try a different flavor, Amazon has a marketplace as well. I prefer using Amazon because I can depend on their shipping, have a Prime account, and trust their reviews (overall, not usually singularly, although occasionally that as well). Learn more about Amazon’s marketplace by clicking on this Lifehack, and delve into the marketplace.
Today's companies don't want to just sell their products. They want to be top-of-mind with customers, generating goodwill and engagement. Many businesses do this by creating newsletters, emails, custom landing pages, social media posts and various other forms of content on their websites and apps across a variety of platforms (desktop, mobile, social, email, etc).
How Much of this Guide Should You Read? This guide is designed for you to read cover-to-cover. Each new guide builds upon the previous one. A core idea that we want to reinforce is that marketing should be evaluated holistically. What you need to do is this in terms of growth frameworks and systems as opposed to campaigns. Reading this guide from start to finish will help you connect the many moving parts of marketing to your big-picture goal, which is ROI.