I have been in Listnerds since day one. I am only a free account so my total number of listnerds is not on the richlist.
I would say that yes Listnerds has helped to build my Hive Power. This is because I get more people to read my post when it is posted in listnerds. I would call it similar to promoting the post.

Typically it will double my rewards on the post and thus my Hive power.
!PIZZA