I am always thrilled and thankful to see new subscribers to my channel. I feel like I owe them at least the customary "Thanks for the sub" message on their channels. Then if I happen to browse their channel's content and like what I see, I will in return subscribe to their channels. That's makes sense right?
Lately, I've been getting a lot of sub4sub tools that are just subscribing in order to get you to return the favor. You'll know these guys when you visit their channels and they have 0 videos and 5000+ subscribers and belong to Youtube groups such as "sub4sub asstards" and "heylookatme.org". So I get it, that's certain peoples' game: create a Youtube account and see who can get the most subscriptions without hosting any actual content. I'm sure it's a proud thing to claim you have an audience of thousands of like-minded time wasters. Cool, good for you.
Now the part that really chaps my hide. When a sub4sub person subscribes to your channel, then you visit their channel to post the standard good faith "Thanks for the sub" comment, then they in turn post a comment on your channel saying something like "hey, sub me back or i'll unsub you."
um, F U and the H you R in on!
That is all...