Victoria's Secret will always sell, because sex will always sell

Fashion editor Alexander Fury discusses the secret behind the American lingerie empire

The Angels gather for the finale

I've been thinking a lot about pants recently. Plenty of people are – and not just because they're something quick and easy to stuff into a Christmas stocking, the traditional autopilot Dad gift.

The pants focus of the moment comes from a rather more high-octane source, namely the Victoria's Secret Fashion Show, which uprooted itself for the first time from continental North America to strut its bewinged, laced and lacy stuff in London's Earl's Court last Tuesday. VS – as it is colloquially known – unveiled its latest load of pants in a fashion show that takes the prize for the most-watched in the world. By some 500 million, in fact.

Doubtless they enjoy the spectacle, but how to justify an event like that, which racks up a price tag of about £9m annually? Because Victoria's Secret's outlay seems minute next to the £4.2bn it turns over.

Smalls are big business, not just for the multi-billion dollar Victoria's Secret types, but for those like Calvin Klein, who reconfigured the basic Y-front into an object of designer lust with the help of a few giant billboards and some racy crotch-shots. It's only a part of the business, but it's massive – they have stand-alone boutiques for the stuff.

When I interviewed Donatella Versace in January this year, she confessed that their underwear business was "'uge" – wink wink, nudge nudge. She's put her underwear out there time and time again – beaded bras at the couture, lace "him-gerie" at her winter 2013 menswear show. In January, she chopped the arses out of her trousers to better showcase bandana-printed pants, £110 a pop.

It's odd, the focus fashion puts on pants when, for most of us, underwear is precisely that – something to wear under your clothes. Something private. Something even a bit sacred. Then again, fashion's always been obsessed with the idea of sexiness, of undressing to impress.

Vivienne Westwood once said: "Fashion is about eventually being naked." Maybe so – and nothing reminds you of that more than a pair of pants. Probably because there isn't much to distract – even when they're accessorised with a pair of Angel's wings. Sex, it seems, will always sell.