You are very correct, when you daily upload your work on social media platforms and you make the links available to all , you are indirectly marketing your work, but make sure you add your signature on any of your uploadbesides being a freelancer, for example, if you have an account on a social media platform, you should be posting your artworks or designs there, you might get a chance to work in a decent company if people like what you are doing, you can't know from succeed can come