If people were that hard up for violence wouldn't they be watching hockey, which is faster and bloodier? No cheerleaders. Seriously, there are guys, esp at the top of the NFL target age, for whom cheerleaders are still a big deal. These guys grew up when naked women were not a simple GIS away. No cheerleaders aren't the primary reason for the NFL's popularity, but time of the week, time of the year, and violence are very very much so. And cheerleaders fit very nicely with that mix.