FAN Facebook Audience Network
http://www.businessinsider.com/what-is-facebook-audience-network-and-why-does-it-matter-2016-2
FAN (Facebook Audience Network) is not FCA (Facebook Custom Audience) which is what you have.
FAN is for mobile app publishers to earn money.
FCA is for businesses who want to advertise on Facebook website and App.
FAN made $1billion last year. But why do you refuse to add to your service?