Tom Murphy recetly had an interesting post on the debate surrounding how to measure the effectiveness of PR.
Measurement continues to be the single area in Public Relations where there is little or no consensus. The sheer variety of metrics used to measure PR performance from hours spent, to advertising equivalency, audience surveys and web hits provides a lot of confusion on how to best measure Public Relations.�
The problem is accentuated by the fact that most PR measurement discussions center on media relations when many programs go far beyond pure media relations.
Murphy also links to a global PR measurement survey that is worth filling out.