'Add to the number of times this action has been performed, stored in the DB'

def incr(self, type, project=None):

    assert (type in IMPRESSION_TYPES)
    day = get_ad_day()
    if project:
        (impression, _) = self.project_impressions.get_or_create(date=day, project=project)
    else:
        (impression, _) = self.impressions.get_or_create(date=day)
    setattr(impression, type, (models.F(type) + 1))
    impression.save()
