keep launching these terrible "promotions"?

http://www.aircanada.com/en/offers/a..._discount.html

This is effectively a $25 coupon each way on flights to Europe (similar to the $50 they offered in J-class a little while ago). By my math these 'promotions' typically work out to be a 2-5% discount on flights at best.

My question is does this actually work on anyone? It seems to me that even the most inexperienced traveler would see through these types of promotions very quickly -- it's unlikely to change buying behaviour, but perhaps people appreciate it if they are already flying?