Bench Scale Advertisement - Shame as a motivator?

This is an ad for a fitness club in the Netherlands, which displays the weight of the person sitting on the bus stop bench for all to see. The idea? Shame the person into joining a club to get fit after such a public embarrassment. The question is, will it be effective? I've covered shame as a motivator on this blog before (see the anti-theft guilt-trip dog dish), but I've never had access to any real data on its effectiveness. It seems that this tactic might make the club seem antagonistic to its would-be new members - but personal trainers frequently employ meaner attitudes to get results from clients, so maybe that's okay? More questions than answers in this post, for sure, but interesting things to think about!
[via Gizmodo]