Word of mouth--could this be how it really works?

The technique marries Watts's two main epiphanies: Cascades require word-of-mouth effects, so you need to build a six-degrees effect into an ad campaign; but since you can never know which person is going to spark the fire, you should aim the ad at as broad a market as possible--and not waste money chasing 'important' people. And it worked.
Is the Tipping Point Toast? -- Duncan Watts -- Trendsetting

So:

Yesterday: try to tell everybody

Today: try to tell the infectors

Tomorrow: try to infect everybody