i'm not sure how the database for Perl Monks is set up, but i suspect that this is not a simple addition. unless every node stores the id of its top-level parent node (in addition to the id of its immediate parent), then multiple SQL queries would need to be made to traverse the tree of children and get a reply count.

this could be entirely incorrect, but i suspect vroom would have added this feature if it weren't near impossible to do easily in SQL.