Recent quotes:

Simulation "proves" Gladwell wrong

They looked at that information spread in several ways, comparing via computer simulation how information moved throughout the networks when it came solely through word-of-mouth within a network ("bottom up"), when it came solely through external advertising or public information ("top down") and when it came through varying bottom-up and top-down combinations. What they discovered refutes Gladwell's concept that network position is always paramount. They found that in instances where there is even a small amount of advertising -- even when it is just a quarter of a percent as strong as word-of-mouth -- there's virtually no difference between the influence of the person at the center of a network and those further out on the string.