"PAY no attention to that man behind the curtain", said Frank Morgan in the 1939 classic The Wizard Of Oz, while frantically trying to distract visitors to the titular Wizard from the fact that he was, in fact, not all he's cracked up to be.

You might have noticed Dorothy making regular appearances on television recently, as she and her friends rock up to the Emerald City in an advert for a high street bank - if you haven't, switch your telly onto a commercial channel and it's highly likely you'll see it twice within an hour.

If you're averse to viewing such nonsense, the premise is this: a 21st Century bank 'employee' has been superimposed into the MGM classic, and welcomes Dorothy, Toto, Tin Man, Cowardly Lion and Scarecrow to the Great and Powerful Oz's castle then tries to flog them a mortgage before kicking Judy Garland out on her ear because she's too young to apply.

Technically, it's a superb use of clever digital jiggery pokery, to the point where you can barely see the join. The recently shot stuff even seems to have been treated to look like it was filmed in glorious Technicolor, with that bright, colourful but slightly waxy look to it.

Not too long ago, the same bank resurrected classic Hanna-Barbera cartoons Top Cat, The Flintstones and Scooby Doo to pretty much the same ends, with the Sixties animated heroes drawn into the high street while learning about reward schemes and different account options.

On the surface, they're fun and memorable - even if you can't remember what exactly they're selling - and get noticed, so a big hand to everyone involved.

However, the cynic in me can't help but think there's more to this than 'let's dig up an old classic we love and use it to sell our brand just because we can'. Cartoon or not, it's marketing, remember, nothing is done by accident.

Nostalgia is a massive selling point for anything nowadays, and the type of people most likely to remember these old Hanna-Barbera cartoons are likely well into middle age or beyond now. I believe advertisers call it 'the grey pound'.

They might not need a mortgage, probably already own their own home outright, but might spend a lot of time watching daytime television or channels that feature these kind of ads. Their kids, however, will be long-since grown up by now, and might not be as well off as they were at their age.

They might be struggling on the housing ladder, trapped in rentals, but long for a lump sum or helping hand that would let them get their feet on the first rung. And that's where a cosy little conversation about that funny advert with the long-forgotten kid's TV characters could take a different turn.

As we're constantly being told, young people today waste all their time buying avocados and taking photos of coffee, so it's up to the bank of mum and dad or grandma and grandad to support them,. That's where nostalgia becomes lucrative. Top Cat, loveable rogue that he is, has only gone and planted the seed of remortgaging the bungalow - Inception-style - in the minds of millions.

Using classic characters to sell stuff is nothing new of course - it's 21 years since Steve McQueen (who had been dead for 17 years at that point), tried to convince drivers that a Ford Puma was as cool as the Mustang from Bullitt, and four years since Audrey Hepburn unwittingly sold Galaxy chocolate to the public two decades after she died.

Still, the resurrection of cartoon characters voiced by impersonators or re-editing old footage throws up fewer moral questions than digitally hauling the lovely Peter Cushing out of his eternal slumber for an all-new performance in a Star Wars spin-off.

It's a technique guaranteed to get people talking, I guess, even if the debate is whether or not classic films and shows of old should be associated with something so mercenary as advertising.

But it's a fair bet that while we all bask in the sweet glow of nostalgia, reminiscing about our favourite childhood shows, the man behind the curtain is giggling to himself and earning far more than we would with a high street savings account.