Participating in Facebook usually requires a separate content strategy because what works on blogs and newsletters just doesn't work on Facebook. As long as it's monitored, Twitter runs pretty well just carrying headline links to quality content. But if you cross-post those items from Twitter to Facebook, your posts will probably be ignored, then become invisible in your fan's newsfeed. MailChimp has a good description of the challenge.

MailChimp: Facebook for Marketers, 2011-Jul-27, by Matthew

The number one thing you can do is to encourage users to take action. You can do this directly by asking for likes and comments, but you can also create the kind of content that compels people to respond. This is an area where your creativity is definitely going to be rewarded.

Another cool way to increase visibility is to encourage connection between your fans. Getting your fans to Friend each other has a multiplying effect on the actions each fan takes. Think of your content like infectious laughter. People tend to laugh more in groups than when they’re all alone, so if your fans can see each other and talk to each other, that laughter is going to spread very quickly.