Post 'Em does not currently log anything in the Sakai event log. The event log is useful both for site statistics (user activity within site, e.g. as reported by the UFP SiteStats tool), and for research purposes when investigating how users have used Sakai, which in turn is important for informing further development.
Post 'Em should post events to the Sakai log (postem.*) for each meaningful user action, e.g.
postem.add = User uploads a new feedback file
postem.view.participant = User views a student's score for a feedback file
postem.view = feedback file is viewed
postem.revise = feedback file is updated
postem.download = feedback file is downloaded
postem.delete = feedback file is deleted
The REF field should include the site id (context) and where the user views a user's score on a feedback file, the target user's eid.