Why do people join social media? More specifically, why do more business types engage in social media?

Ultimately, for nearly all corporations (and you could argue with me if I'm wrong) it is to improve the company bottom line. With the shift in marketing towards digital channels, social media being the large piece of that pie, organizations are opening Twitter accounts and starting Facebook fan pages because...it just makes sense.

"If everyone else is doing it, we should be too...right?"

Not necessarily. I've posted before that social media isn't for everyone. However, if it is for you and you've gotten the ball rolling, what should you say? I feel the biggest mistake any web 2.0 beginner could make is to use their channels as a megaphone for themselves. Sure, it is okay to mention some stuff you have done on there from time to time but it shouldn't dominate your social media communication efforts. Imagine going to a party and having one guy in a group conversation doing nothing but talking about himself. Get's pretty old right? When a company promotes only what they do on Twitter or Facebook, it causes essentially the same effect in the social media conversation as well. 

The best social media practices are typically unselfish in nature. Retweet what other people are saying on Twitter. Respond to others' tweets with your thoughts and initiate thought provoking conversation. When posting on Facebook, ask questions to your audience. Talk about things that apply to them to and not just directly to your brand or organization.

Blog commenting is a huge unselfish practice that generates goodwill among other Web 2.0 users. It shows that you are listening to what they are saying and clearly want to engage in their conversation. Comments shouldn't be dry and vague as only saying "great post!" but should genuinely provide input for their topic and continue their conversation. Avoid using the comments section of a blog to post links to your own stuff, as this will definitely give you a spam label.

So why does unselfishness matter? Credibility. The more you self-promote or broadcast your own message, the more spam-ish you come across. The more spam-ish you are, the less people are willing to trust you. People only do business with people they trust. Is it wrong to do unselfish things in hopes that good karma will swing back your way? Absolutely not. However, if what you do for others is ONLY motivated by what you will get in return, it will come out in your communication. People generally have good BS radars when someone is or is not being genuine.

How do you all use social media unselfishly?