UPDATE: As I mentioned below, and as Saydrah noted, we removed the posts that were already in your feed from the Popular page. However, the 'popular' algorithm did not jive well with the remaining data. In short, it was weighing recent activity too highly. As a result, the popular page posts didn't seem so popular.
I've made some changes to the algorithm. My first impression is that the result is more satisfactory, and more fitting of the term.