What's the salient difference between a follower and a subscriber on social media?

[Brajet]

Though followers and subscribers are somehow related, they are different. While followers can be seen as regular users, who see contents in-feed on a regular basis, subscribers often paid or opt in, gaining access to exclusive contents.

Those that subscribe would be given some preferential treatments compare to those that just follow. However on some platforms, both subscribers and followers are treated the same way.

Do you know any difference between a follower and a subscriber?