> the exact same posting seems to generate a better response if made under a newly invented pseudonym

My experience on USENET is that a psuedonym that looks like a real name (Kurt Wallich or Crowder Thompson) gets more respect than an obvious psuedonym (LargeSpaceMonkey or Gravedigger) which still get more respect than psuedonyms that are unpronounceable or illegible (gR9jmlcrq or §¥ww«)

throop