Groups such as al-Qaida (AQ) have pursued spectacular attacks to garner media attention and popularize their cause. What is often not noted, however, is that for those who submit themselves to the religious thinking of al-Qaida – and nowadays the self-designated “Islamic State” (IS) – the militant struggle is intertwined with the duty to call upon others to join the movement (da’wa). For jihadists da’wa is obligatory. While AQ’s central organization pioneered the use of bulletin forums, blogs, YouTube and to some extent Facebook, for this and other purposes, it was its Syrian branch, Jabhat al-Nusra, that in 2012 pushed effectively into Twitter use. AQ lost its momentum as the social media pioneer of jihadism shortly thereafter to IS. Since 2013, IS has taken the use of social media da’wa and other activities to the next level. From that point onward IS has very effectively projected influence on Twitter on a massive scale, reaching a global audience. Since early 2016, however, IS’s networks on Twitter have been degraded by various counter-measures, but the group has reconfigured and shifted to a new social media outlet: Telegram. This application has become the most important information outlet for IS and has been used to recruit and guide attackers in Europe. This article takes a closer look at what Telegram is, and how IS uses it for different purposes: not only operationally, but also for identity building.