by Jason Caldwell » June 14th, 2011, 1:15 am
s2Member Pro will export ALL Custom Fields, on a Per-User basis. That is, if a certain User has a Custom Field, it will be exported, even if it's empty. That being said, Cristián is also correct, because in the latest release of s2Member, if a User and/or an Administrator updates a User's Profile with a Custom Field empty, s2Member will NOT store any Custom Field that is completely empty. So depending on what version you are running, and depending the last time a User's Profile was updated, you may or may not receive empty fields in the export file.
We'll try to improve upon this in a future release. In fact, there are several things already being worked on that are related to Custom Field improvements overall.