This document discusses strategies for incumbent companies to compete against free offerings from competitors. It outlines three factors for assessing the seriousness of a threat: 1) growth rate of users of the free offering, 2) ability of the competitor to cover costs quickly, and 3) speed of incumbent's paying customers defecting. It then presents four response strategies incumbents can use: up-sell, cross-sell, charge third parties, and bundle. Various case studies are provided to illustrate how companies have successfully implemented these strategies, such as Netflix introducing a free trial period to habituate users before charging a subscription. The document concludes that incumbents must assess the threat level and react accordingly to either defend their business model or co-exist