Bob Wyman: I did a quick analysis of the pings that we receive daily at PubSub.com to provide some context and data for further discussions. As would be expected, when one plots the number of pingers against a ranked ordering of the number of pings received per pinger per day, what results is a power-law curve. [cut] 33% of pings were generated by only 1% of all pingers -- many of them "spingers"...

http://bobwyman.pubsub.com/main/2006/04/stats_on_pinger.html