I don't download much CC but each time I do it has been inspired by feeling unsatisfied/annoyed about something. Like how I was trying to choose my fresh new teenager a hair and feeling like none of them suit him. So off to the lands of CC I went. Not a coincidence that my CC interests are vastly dominated by masculine hair/clothes, facial hair and tattoos. Sometimes I might stumble upon and grab some nice looking hair for ladies too.
I have never downloaded any BB content though. Don't care enough for build/buy in general so I have never been left with a feeling of "something I need is missing".