If you've made the decision to participate in an online community or social network, whether it's a support forum, Twitter, Facebook, LinkedIn, or some other place where people gather online, then you need to be digitally present.
Every day, I send personal messages to folks who follow my Twitter account, only to receive back an automated "thank you, please check out my ebook and fan my Facebook Page." It makes me want to unfollow immediately. And cry.
Same thing with responses in support forums---you can tell when a representative is pasting a canned response into the posting box. They refer to themselves with a Royal "We" rather than "I" and it often ends with grammatical astroturf..."have a nice day."
If you've got your social networks on autopilot, with feeds going directly from blog to Twitter, or from Hootsuite to Facebook, you're shortchanging yourself. Your brand presence is no more real than one of those cardboard cutouts at the movie theater.
My advice is to not even bother setting up an outpost unless you plan to actively participate. It's better to not be there at all, than to have the lights on with nobody home.
Awesome robot photo licensed under Creative Commons from Flickr user jdhancock.