From Kings College ICSR a short commentary that ends with:
Put together, there are signs that IS’s much vaunted media machine has declined over the past half year. It remains very active, of course, but there seems to have been a peak between mid-spring and mid-summer this year. This, I believe, could be indicative of other structural issues IS could be having on the ground. It also suggests that military victories rather than counter messaging has a stronger effect on the media capabilities of jihadi groups.
Link:http://icsr.info/2015/12/icsr-insigh...-media-output/