Anybody using sub4sub to build YouTube subscribers?

Someone saw a video of mine on YouTube and sent me a message saying that he liked it and suggesting that I may want to try sub4sub. I looked it up and it's basically like Twiends (where you follow others and then you get followed and it's based on a points system) for YouTube. You subscribe to people and in exchange, they subscribe to you. Similarly to Twiends, you can buy subscribers as well.

My question is, does anyone know if this violates the TOS at YouTube? if it does, I don't want to do it. If it doesn't, I see no harm since since it would help me build a list of subscribers.

I realize they wouldn't be targeted subscribers, but I don't really care. It's a herd mentality thing. When people see you have over 1,000 subscribers, they are more likely to want to subscribe as well because they figure it must be something good. When you have low views and no subscribers, it's that much harder to build a list of subscribers to the point of being something that can snowball on itself.

OTOH, if it does violate the TOS, it's not worth taking chances of being caught. So, anyone used it before? Anyone know anything about it?

Thanks in advance,

Eric