Last week the Intercontinental Hotel Group organised a global gimmick to launch largest ever free rooms giveaway promo.
The "the world’s biggest bed jump" had thousands of people jumping (for 16 hours) on four of the world’s largest beds, in four countries - London, Shanghai, New York and Paris.
This is London...
... pity it wasn't "the world's largest pillow fight"! That might have been fun.
Anyway, it worked, because I've mentioned the promo here, and here.