» Celsys are going to start charging for software updates to their popular Clip Studio Paint product

» The way Celsys communicated this to their users caused outrage — some of which was justified

» Fog Creek found themselves trying to monetise their viral product Trello, which it had promised would be free forever

» Fog Creek had first mover advantage on an easily copied product, which it exploited by a timely sale to Atlassian