Let's think about this...

Do the "midrange" Popular PR, say; 4-6 get bled off to Paid Advertising to some extent... That is the apex (highest percentage) of the "Bell Curve" in popularity, isn't it?
6 or 7 is "teetering" on "trusted site status", and then you start to "blow out" from there on the "downslope" of the "Bell Curve". That just doesn't seem too absurd to me at all!

Why not?

Ken