Everyone recognizes that trust is paramount for establishing credibility in social media messaging. But how do you build trust in a medium where online identities may be little more than a logo and a few lines of copy? If you text, you already know: responsiveness. When someone sends you a text, if you want continued interaction you need to respond — and the quicker the better. Blogger Greg Ferenstein points out that when only text is available, participants judge trustworthiness based on how quickly others respond. So, he reasons, it is better to respond to a long Facebook message acknowledging that you received the message, rather than to wait until there's time to send a more thorough first message. Wait too long and you are likely to be labeled unhelpful or, worse, a host of expletive-filled attributions. To increase your social media responsiveness, Ferenstein suggests making sure Facebook, LinkedIn, et al, send you e-mail alerts. Then, only archive the e-mail once the message has been responded to.