But it is your experience that is lacking. You need to have a better understanding of marketing and all the various options for doing what you do. More money too most likely. The problems you face are not new. Lots of folks have solved them already.
That is a bit condescending, uncle BirdJaguar ^_^
Most people aren't much into inconvenience. You can ask all you want that they join some less known platform, but they more than likely won't bother - and this will affect sales as well.
Besides, I am not a salesman. I only create the product to be sold. If I felt like having my own company I'd go for that route (which would bring more money for each sale, but possibly a lot fewer sales overall - I still may try it in the future...)
(although I actually am not at all keen on selling stuff myself - I am pretty terrible at that!)