They’re not “undisclosed”, they are just untapped. Consider Instagram, there was a time when it didn’t have as much advertisement as it does now. In those days

They’re not “undisclosed”, they are just untapped. Consider Instagram, there was a time when it didn’t have as much advertisement as it does now. In those days you could cheaply advertise a product through someone with a high follower count. As more people started doing this, demand went up and so did prices, and then standardization came in. Now it takes big money to advertise effectively on Instagram.