Heads up, Creators: On Dec 13-14 you may see a noticeable decrease in your sub count as we remove spam subscriptions. If spam is removed, you'll see a YouTube Studio alert: https://goo.gl/qGDBvX This should help give you confidence that the subs you do have are real fans!
"How can do we know what a spam account is? Well, our handy algorithm determines that!" Cool. Software. That always works out well and doesn't backfire. You gotta get some positive feedback to put in your next Rewind.