Spam economics: Why is there so much spam? According to this article, it's because spam is still a money maker for the spammers, despite a measly 0.00036 percent conversion rate, which the author calls the "Barnum rate" (after PT Barnum's famous saying that "there's a sucker born every minute"). He calculates that despite this low click-through rate an aggressive spammer could make close to $100,000 per year. (Via Techdirt.)