Currently once members join, they no immediate need to fill out additional profile fields or keep it updated.

New Feature Request: Many membership sites have a % counter called Profile Complete so you can track members completing their profile. This should be a metric only available for administrators so you can email members without 100% complete and be able to search for these members and email them. Also their should be a gadget that you can add to member only pages to notify current logged in user of % profile complete until it reaches 100% complete.