From a posting by Phil Wainewright - sick but true:

If the experts are right, SoBig probably also qualifies as the first profitable, mass-market, commercial application of the principles of grid computing. It cleverly exploits the loosely coupled characteristics of a highly distributed, massively redundant grid architecture. Especially impressive is the utility provisioning mechanism that supplies new reserves of raw power to the SoBig grid, instantly able to draw on the never-ending supply of imprudent users whose curiosity about the contents of a suspicious attachment will always override their caution.