"Exterminating the nuisance of spam"

CNet's article, "Exterminating the nuisance of spam is an interview with Suresh Ramasubramanian, head of Outblaze. Outblaze handles spam for Mail.com and Register.com. The article states:

What's the single most important thing that can be done to stem the flow of spam?
Ramasubramanian: If I can get even one fraction of a percentage of e-mail users to stop clicking on attachments . . .