Experts say this is because as a perfume dries on your skin it releases a sequence of odours.

The lightest, head notes , appear during the first 15 minutes. These are followed by heart notes, and finally the base notes, which appear in the last 12 hours.

So what a scent smells like in the shop will differ after a day at the office.

Celebs aren't the only ones getting in on the act - for fashion houses it's a lucrative sideline.

In a year when Burberry clothing sales were down, its profits went up 17 per cent - due to perfume sales.

Designer Yves Saint Laurent once confessed that perfume made up 85.3 per cent of his house's revenues.

Meanwhile, glittering marketing campaigns and TV ads promise that we will become fatally alluring and utterly irresistible - if only we smelled just that little bit better.

And due to the financial importance of perfume advertising, our favourite glossy magazines never print anything remotely critical.