It always is amazing to see how different people figure out ways to make money online. It really can be as simple as finding a very narrow niche that does not have too much competition, learning how to do some keyword research, finding some products to promote, and then learning to build a simple website or blog.
If you think this is a crazy notion, then here is an example for a very narrow niche on selling something as simple as aprons. Do a search on "buy cute aprons" and see what shows up in the search engines (namely Google).
Here is another example I came across and decided to add on something as obscure as the term, scarecrow sprinkler...you can't get much more niche-market than these two examples. I found these just doing some arbitrary searches. This should show that there are literally thousands upon thousands of niche products that can be marketed online.
That's how you start a home-based business online. Do you think you could do this over and over, and maybe just build one website a week to sell a unique product or service?