Thanks to Chris on the most recent article from Harvard Business Review on "How Valuable is Word of Mouth?" (you're right, how did I miss this one?).
Consistent with our not universally-accepted preachings, the HBR article has some very well-reasoned conclusions based on research of 15,000 customers at a telco and financial services' firm:
- Optimal word of mouth referral and the best overall value to a company doesn't come from your most profitable customers but from the rung below them that drives significantly more value by championing quality word of mouth referral
- Referrals are extraordinarily valuable - the annual profit gained from a customer's referral far exceeds that customer's entire lifetime value
- Word of mouth programs designed to build advocacy are extremely profitable with 13x to 15x return on investment
They also offered up a prescription for how to deal with each segment:

Missed here is also an inherent opportunity among "champions" to turn them into formalized brand ambassadors/community members and enhance and improve their purchase experience and referral influence through innovation, value added services and formalized community building.
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