What is "black hat" and "white hat" technique?

What's the general consensus on retweet networks? Is it a black hat technique, or is it legit if you make sure you're only retweeted by relevant sites?

• One of the accounts I handle was invited to an industry-oriented retweet hub. If we participate, we have to retweet participants' tweets. They have to do the same thing for us, but it could clutter up our feed. On the other hand, though, we're currently working on growing our influence, so this could be beneficial. I'm leaning toward not participating in this, but I'd like to hear what others think of the idea.

• Answer:

  To answer this, you simply have to consider how social works... Your followers "signed up" because they find value in what you have to say and you find value from continuing to have them engage, share or just respond back to your posts. Your efforts live, and die, by your content. You don't need more eyeballs, you need the right ones. This being the case, what you share must remain relevant to your audience at all times. You don't gain influence by being shown to people who don't care what  you have to say any more than you keep what you've already built by showing your followers things they don't want to see... but you do stand lose their attention and very likely their following. Thus when you say "network" and "have to" I'm immediately skeptical (ok, I'm not a fan, at all). If the tweets you're suppose to push out there bring value, post them, that's already a win (back to content ruling)... If they keep being a fit, build it into a partnership yourself... you and the other brand... not by formulas or games but collaborative value. Otherwise what's the point?