Everyone with a good idea wants it to have impact, but why do some social innovations go global whilst others remain small-scale? Whether their idea is a pioneering schooling model or a new form of volunteering, social innovators must become campaigners and embrace change in order to have widespread influence. Innovators who can campaign for an idea create demand amongst those who might benefit from it or help support it. Being willing to experiment with an idea is also critical. Experimentation pinpoints adaptations needed for an innovation to spread beyond specific sets of circumstances. Likewise, innovators must be ready to let their ideas grow beyond their own organisational boundaries. Most social innovations spread through copying rather than through building the social equivalent of big corporations.