You find out what is of interest to them, and you craft your offerings to those interests. Well, there are two basic ways. The second is to try many different messages, measure the responses and eventually you may find out what works best, and by deduction, conclude that whatever it is that they are responding to must be what interests them. This is a tremendous waste of time and money, but this is exactly what many businesses do. No wonder so many new businesses fail within the first five years.
Some marketers take the first approach to a next logical step.
They believe that you need to identify a narrowly defined target market, and then find out what that group ultimately wants and needs. Then and only then, do you go find the solutions to the target market problems and offer those to the group. Come 'n get 'em. In fairness to Nicholas, as a marketer, you need to start somewhere. And your area of expertise is probably the best basis for you to be able to offer something of value to others.