Strive for many narrowly defined audiences rather than bucketing everyone into a few broad categories. (contentmarketinginstitute.com)
I've come up with a few broad categories and some examples of each (but once we pick a genre I can be more creative in finding books within it): (thelunchtray.com)
In general, hormone dysregulation that leads to acne can be broken down into a few broad categories: (paleoforwomen.com)