A brand is defined by the sum of experiences a consumer has with your company. That means no one in your company/organization is exempt from being an a brand ambassador/advocate. On top of whatever role they play they also play an integral role as advocates and influencers in their every day lives.
As humans we naturally want to share information with each other and since every person, place or thing can be made into a brand chances are you’re already advocating for one or bringing down another in someone’s view.
Culture can be described as actions induced with meaning repeatedly passed down. Similar to habits with the exception that it marks/labels you as a part of a certain group. There is exclusivity involved. People like this, who believe x,y,z do this. What else does this sound like?