Why are philosophy departments so good about disclosing job placement of PhD graduates?

I told this story back in 2008, but some recent chatter on Twitter made me think it's worth repeating:

Colleagues in other fields are often impressed by how much information about job placement philosophy departments now make available on their web sites.  It was not always that way, alas.  About six years ago [i.e., before the blog circa 2001-02], I used the Update Service [a large email list] to the PGR--which reached several thousand philosophers--to suggest that departments be more forthcoming about this information, citing some models and indicating that in future editions of the PGR I would call attention to departments that were not providing such information, since that should surely be a warning to prospective students.  Departments, for the most part, reacted constructively and did the right thing, posting information about recent job placement on the web.  

And that, prospective philosophy students, is why all departments list job placement information, although there is still some variation in quality, but mostly it is pretty good.