I was going to write exactly the same thing Peter did— yes, very useful!
As I was reading your post, I kept thinking about the “weakness” that you eventually described in the penultimate paragraph. The decisions about the boundaries that define “what we think is popular” are a really interesting factor—it’s almost more about who you (the site / online community) are then about what’s the right way to define popularity. E.g., do you see yourself as one cohesive group, or as many groups, or just as many individuals?