It varies. it really varies.
Really depends where exactly you are posting and who you are posting to. For example we became fairly known in the payday 2 community due to me doing collaborations with some of the games developers. That gave us some good growth and subs in the beginning when we first started.
If you post your video with a snappy title people are likely to click and youll get views. If you post something like 'SUB TO ME PLZZZZZZZZZZ' People will just downvote you into oblivion.