Mather,
This is the kind of exotic plant that appeals to serious plant collectors, such as myself, who are always looking for the unusual, and appreciate plants that are "off the beaten path". You are right, plants such as Pond Scum do not appeal to everyone, which is why you will not see the like at Home Depot or Wal Mart, but must haunt the specialty nurseries such as Plant Delights to find these jewels.