Very few here will be able to answer this question, because most of them have no idea about marketing, but if you are using Google Analytics in any of your sites it may help you.
On the left side there is this part called "audience" where you collect a bunch of information about your visitors, from sex, to age, language, geo location, etc... this information will help you to understand your visitor and buy advertising where they have a simmilar demographic audience, that is exactly what the tool is for.