urchase ▁and ▁refer ral ) ▁to ▁a ▁product , ▁service , ▁brand , ▁or ▁company . ▁Reich h eld ▁and ▁Mar key ▁developed ▁the ▁method ology ▁by ▁comparing ▁the ▁ability ▁of ▁several ▁different ▁questions ▁to ▁predict ▁future ▁purch ases ▁and ▁refer r als ▁of ▁individual ▁respond ents . ▁They ▁chose ▁the ▁lik elihood ▁to ▁recommend ▁question ▁based ▁on ▁the ▁observation ▁that ▁it ▁best ▁predicted ▁these ▁customer ▁behav iors ▁in ▁ 1 1 ▁of ▁ 1 4 ▁indust ries ▁studied . ▁They ▁also ▁found ▁that ▁differences ▁in ▁Net ▁Prom oter ▁Sc ores ▁among ▁direct ▁compet itors ▁in ▁a ▁market ▁could ▁explain ▁substantial ▁differences ▁in ▁re venue ▁growth ▁rates ▁among ▁compet itors ▁in ▁a ▁particular ▁market . ▁Import antly , ▁Mar key ▁points ▁out ▁that ▁" comp et itive ▁benchmark " ▁Net ▁Prom oter ▁Sc ores ▁collected ▁through ▁a ▁carefully ▁constructed ▁double - bl ind ▁Quant itative ▁market ing ▁research ▁method ology ▁provide ▁the ▁only ▁valid ▁basis ▁for ▁comparing ▁scores . ▁ ▁Net ▁Prom oter ▁System ▁also ▁requires ▁a ▁process ▁to ▁close ▁the ▁loop . ▁In ▁closing ▁the ▁loop , ▁the ▁provider ▁act ively ▁interven es ▁to ▁learn ▁more ▁from ▁customers ▁who ▁have ▁provided ▁feedback , ▁and ▁also ▁to ▁change ▁a ▁negative ▁per ception , ▁often ▁converting ▁a ▁Det ractor ▁into ▁a ▁Prom oter . ▁The ▁Net ▁Prom oter ▁survey ▁will ▁identify ▁customers ▁who ▁need ▁some ▁follow - up , ▁including ▁Det ract ors , ▁and ▁should ▁automatically ▁alert ▁the ▁provider ▁to ▁contact ▁the ▁consumer ▁and ▁manage ▁the ▁follow up ▁and ▁actions ▁from ▁that ▁point