The song is widely rumored to be about Courtney Love, whom Trent Reznor credits with destroying the friendship between himself and Tori. In 1999, Reznor's band Nine Inch Nails released a single called "Starfuckers, Inc.", with "Starfucker" being a word that appears in "Professional Widow".
According to that other site this single was issued as a limited edition of 2,500 but several hundred of these were subsequently destroyed in a warehouse flood.