I read this post from Seth Godin last week and it has continued to be on the mind since.  It is framed around how frequently you should publish be it personal (ie blog) or professional (ie company news/updates).  The notion of a "frontlist" and a "backlist" relates to the type of content that is created and where that content resides.

If you embrace the Long Tail concept, this will make sense.  If not, then here is my attempt at simplification.  The frontlist is what, traditionally, the target of PR efforts has been focused on – the front page of the WSJ, a CNN interview, etc.  The backlist is the rest of the discussion generally fed and guided by the frontlist but is a place where the conversation takes place about you – self-generated or otherwise.