So Yahoo's social network expert Duncan Watts, author of Six Degrees, doesn't rate 'influencers'.  Armed with computer models, he's challenging the idea that innovation and marketing dollars work harder when they are invested with the trendsetting lead users in your category. Better to cast your net as wide as possible and cater to the mainstream majority ("mass seeding") rather than focus on fickle influencers and even more fickle network effects.

So what does this have to do with your Net Promoter strategy of achieving increased growth by putting the voice of the market at the heart of the business decision-making process? Well, it's all about deciding whose voice you should be listening to. Should you listen preferentially to lead users (influencers), because they act as gatekeepers to mainstream adoption, or should you listen to the mainstream majority because they make up the volume?

A case can be made for both -- but I'd add that it's the voice of the money we should really be listening to -- hardwiring the voice of your most profitable users (or the category's most profitable users in the case of new product development) into the business, rather than that of average or lead users. Why? Because it's profitable users, not lead users or average users that drive profits. If you want to segment further, then the Net Promoter Grid (below) will direct your listening to profitable promoters (because of the extra referral value they represent) and profitable detractors (because of the risk value of losing them).

An interesting example of putting this into practice is the leading UK cosmetic brand 'Simple', which has recently set up an online 'promoter panel' of high-spending brand fans to help them innovate.

Rather than try coolhunt influencers such as trendsetting fashionistas for the panel -- the company is following the money and putting the voice of profitable promoters at the heart of their business decision-making processes. Feedback (rewarded by an online e-shop selling Simple products at staff prices to panel members) has already led to the development and successful launch of a new product.

So if you get the opportunity to spend time with profitable users, lead users, or average users -- I say follow the money.