ISIS is more than beheadings, and works hard to gain the subjugated allegiance critical to its continued existence.
"...one week of official media releases of the Islamic State (IS)...provides a snapshot upon which to better understand the different styles and messaging streams IS releases on a weekly basis. ...IS produces much more material, and on a broader range of topics, than what gets reported in the mainstream media. Execution videos make up just a fraction of the overall output and are dwarfed by the number of IS productions on military affairs, governance, preaching, moral policing, and other themes. The analysis also shows that IS relies very heavily on visual as opposed to text-based propaganda, and that most of its military activities take place in Iraq, not Syria."