. . . when public website users perform simple Internet tasks, they’re successful two-thirds of the time on average. In other words, users fail 35% of the time . . .
Six sigma tolerates no more than 3.4 defects per million manufacturing opportunities; in contrast, the Web generates 350,000 defects per million interaction opportunities. The difference between the two quality levels is a factor of 100,000.
The only reason the Web works at all is that people are flexible and persistent enough to try again when their first attempt fails.
The good news, I suppose, is that the opportunity for improvement is virtually limitless.
Thus spoke The Programmer.