Up to the present Facebook has had around 2 billion active users around the world. That is about six times the population of the United States, almost 30% of the world population. Ever since they acquired Instagram, Facebook have easily become one of if not the biggest social media platform in the world.
It is not only the sheer number of users, but the amount of attention Facebook owns; one hour a day is the amount of time the average user spends on Facebook.
Numbers don't lie. Sooner or later you must make full use of this massive attention to grow your business.