Your business should solve a bigger problem. What you are doing is fine but it's very hard to market a very specific skill. What you want to do is first identify WHO your perfect customer "avatar" is. Write that down and even give that person a name. What business do they have? What kind of income do they have? What are their biggest business problems? Then pick a problem to solve. I'm betting that your specific skill is part of the solution for a particular problem but you have to work deductively, meaning large problem first (for the marketing) then work on the small things after they become as client. If you try to market that specific skill it won't go anywhere as you have seen.