A good marketing strategy may multiply your clients by 10 or more, but any quantity multiplied by zero is still zero!.
This means that if, after a reasonable amount of time, you have absolutely no customers for your product, maybe the problem is not the marketing of your product but the product itself.
Sometimes people (i.e. myself, see below) are really stubborn and when they don’t sell they always think it’s because they need one more feature or buy more in ads or … when in fact the solution is much simpler: nobody cares about your product. Stop! It’s time to go back to the drawing board.
It took me a while to realize that I was one of them. After seeing that I had no (paying) users for my code generation services I started a complete revamping of this part of the site, convinced that the reason of my (for sure temporary 🙂 ) failure was the way to introduce and motivate the services, the look and feel of the site,… However, in the meantime, I launched my second project, and to my surprise, with almost no publicity and a very simple web page, some people purchased it almost immediately. Sure, we are not talking about hundreds of customers but still, if in three weeks with a project B you get more income than in one year with a project A then IMHO the market is telling you something.
So, if you don’t sell, think twice whether the problem is the marketing or the product. In the end, only the product can make the difference, especially if you, as most of us, have a limited marketing budget.