In the example of the Body Glide the solution already exists. This is true for many common problems, but people don't have the time to do the research to find a solution.When you take the time to find a quality solution for their problem you are already on your way to earning more money.
However there may be a problem that doesn’t have an existing solution. This is often true with processes that are difficult. One example is homework. I have never met a parent yet who didn’t complain about helping their kids with homework. I happen to have a degree in Elementary Education as well as 2 children so I felt qualified to write an Ebook with tips and techniques for parents to get their kids to do homework. I created a website for the book and started selling. Because I am active in my children's classroom I was able to persuade the teacher to include a link to my book in her weekly email home to the parents. I was able to combine my personal knowledge with my life and provide a solution directly to the market that needs it most.
If you have some expertise or knowledge you can create your own solution. It doesn't have to be an ebook. You could create a video tutorial or a podcast. Whatever method you are most comfortable with.
If you don’t want to create your own product you can check for solutions at places like Click Bank and JVZoo where there are many ebooks and other electronic solutions available. Make sure you are selling quality items though or you won’t earn more money, just a bad reputation.