From the "PR Wall of Shame…"

Sometimes I am absolutely in awe of the arrogance and stupidity of some PR firms.
For several weeks now, at three different email addresses, I have been getting spammed by somebody purporting to be organizing an automation exhibition in Egypt in March of 2007.
I have repeatedly emailed the individual, from each mail address to ask them to stop, since I won’t be attending the conference, won’t be submitting a paper, and won’t be buying exhibit space there. The only thing that happened is that I’ve started getting several a day of these announcements, rather than just one.
Please understand that I don’t have anything against the idea of holding an automation exhibition in Egypt, next year or any other year, nor am I entirely opposed to attending sometime. But I won’t be going next year.
If this individual doesn’t stop spamming me, I won’t be going anytime, and I might even consider getting a voodoo doll with his logo on it.
Why, I ask you all, would a supposedly professional communicator continue to engage in this incredibly counterproductive behavior, long after it should be obvious that it IS counterproductive?