I'm going to give you the benefit of what took me years to figure out on my own. This is one path to success in the information age. Every known media uses it to sell virtually anything. I can boil it down to one word.
Content is information that has a high value to a targeted niche.
Your content is information in which you have a special expertise. Its value comes from the fact that you know it and others don't. Give First, Then Ask. Good content has the power to set you above the crowd as an expert. Communicating your passion through your content is your own personal key to attracting targeted traffic to your web site.