caribguy - 4:36 pm on Aug 9, 2010 (gmt 0)
IMO a 'good' update contains a value proposition for the reader: e.g. something useful, news, funny, interesting, unique...
Does not always have to contain something actionable or a sales pitch. As long as it creates a positive association between the message and your brand/product.
Trackback earlier updates and count likes + comments to get a rough idea of what your audience wants.