Funny how the world works
Using sex in advertising works, but it's a low, loooow level of creativity from the ad agency. If I'm paying agency creatives a ton of money to build a campaign, and they come back with "we'll get some chick in undies and put your product somewhere nearby", I would be questioning their capability. A three -hour lunch and en expense account and you come back with...boobs?
As far as the UK market goes, using humour seems to be the path to a classic ad. I still have nightmares about this one: http://www.funnyplace.org/stream/pot-noodle-luxury-20032/