When VCCP chose Simon Greenall as the voice of Aleksandr Orlov, the star of its now extremely successful Comparethemarket.com campaign, it is unlikely the agency anticipated the excitement that the unveiling of his identity would cause.
Greenall, best known for his role as Alan Partridge's friend Michael in the sitcom I'm Alan Partridge, is far from being a big star - but his relative fame was enough to get the story into a number of national newspapers.
According to the VCCP creative director, Darren Bailes, the agency's search for the right voice took more than a month, and went through various authentic Russian and even Polish candidates before opting for Greenall. And, Bailes says, his selection was not in fact based on his fame as an actor: as Aleksandr, Greenall's voice is completely unrecognisable.
But there can be clear benefits to using professional actors rather than specialist voiceover artists for this kind of work, agencies say - despite the potential extra cost attached.
Ben Walker, the creative director at Wieden & Kennedy, which uses the distinctive tones of Rutger Hauer and the gravel-throated Garrison Keillor for its Lurpak and Honda ads, says he much prefers working with well-known actors.
"I would steer clear of anyone who makes a living from voiceovers," he says. "The advantage of working with Keillor is that he has the most amazingly rich voice and he will read out your copy in a way that's totally different to how you imagined it when you wrote it. When that happens you know you've cracked it. Same with Hauer: he's not interested in doing a typical voiceover. The pair of them provide a filmic quality, which we think lifts the work."
The Leo Burnett team Ed Morris and Andy Drugan, who wrote the recent "drug driving" campaign for the Department for Transport, picked Jonas Armstrong, the star of the BBC's recently axed Saturday-night drama Robin Hood; partly because his age was suitable for the audience he's talking to and also because of the tone in which he delivers the message.
Morris says: "We wanted to get the message across in a non-judgmental way, so we chose an actor because some voiceover artists get behind a mic and turn into a selling machine."
Costs vary wildly. While there are certain stars who can charge £5,000 to narrate a spot for those advertisers that are willing to pay the price for a specific voice, the average fee is modest at between £200 and £300 for studio time. However, extra earnings calculated by TV repeats can bump up costs if it's a high-profile campaign.
According to Martin Sims, a creative director at the specialist radio agency Eardrum, the ad industry has always tapped into whoever the current favourite comedy acts are, from Men Behaving Badly to The Office and Little Britain to the The Mighty Boosh - but this can lead to ads sounding far too similar to each other, he warns.
"Agencies could cast with more care," Sims says. "The industry gets in a rut when everyone has the same idea for Gavin And Stacey or everybody wants a Garrison Keillor voice. We get a call twice a month saying we want someone like the bloke in the Honda ads."
And there are plenty of other times when a professional voiceover artist with the right skills can be a better choice than going down the celebrity route.
Simon Blaxland, a freelance radio producer, says: "If the client is a newspaper or a retail brand that needs immediate turnaround tactical ads, then a celebrity who is on location for most of the year may not be there when you need them. The critical thing is not whether the voice is a celebrity or not, but whether they are the very best for the ad or campaign."
The fact remains, though, that there is a select group of celebrities who remain eternally popular.
Stephen Fry narrated last winter's flu vaccination spot and he also voices M&C Saatchi's current ads for Direct Line with Paul Merton. Fry's QI co-star Alan Davies was originally cast as the mouse in the ad and the show's producer John Lloyd was drafted in to direct it because the agency wanted to replicate the QI chemistry. However, Davies declined and Merton stepped in.
"I'm not surprised people use Stephen Fry as he's a consummate professional. He's witty, he delivers in one take, adds a lot to the sessions and he's great to work with," Paul Pickersgill, a senior writer at M&C Saatchi who worked on the campaign, says.
Other newly popular voices are the Gavin And Stacey writer and star James Corden, who lent his voice to some recent Orange ads for Fallon, and David Mitchell, the voice of Pablo the drug mule dog in the spots for the Government's drug helpline Frank by Mother.
Brian Jenkins, the head of audio and radio at COI, says that while government ads often use celebrities such as Fry, Mitchell and Sue Johnston, who narrated the "act fast" stroke campaign, it is because of the quality of their voices rather than their fame.
"Just because they're famous doesn't mean they can read a script properly," he says.
"In radio, we're looking for someone who's going to sustain the listener's attention for 30 seconds, so they've got to be good at bringing a script to life for that period of time."
CAMPAIGN'S TOP TEN CELEBRITY VOICEOVER ARTISTS
1. STEPHEN FRY
Credits: Direct Line, NHS, Argos, Tesco, Orange, Coca-Cola
Fry, the host of QI and star of numerous TV shows, is a perennial favourite with advertisers, whether as a voiceover or in person. He's rarely been off our screens: from a 1988 appearance in a Panama cigars ad to his most recent voice work for Direct Line pet insurance. Fry is now so popular, he's blown his former comic partner (and past king of voiceover), Hugh Laurie, right out of the water to take the top spot.
2. DAWN FRENCH
Credits: Tesco, WH Smith, Food Standards Agency, House of Fraser, Batchelors Cup-a-Soup
Probably best known for the Terry's Chocolate Orange spots, French has recently upped her ad appearances after a dry patch during the mid-2000s. In the past year, she's added her voice to spots for a wide variety of companies, including Tesco (Christmas and Easter ads), WH Smith and, most recently, a foray into the world of online gambling with an ad for Foxy Bingo.
3. TIMOTHY SPALL
Credits: Wickes, Tommy's, Tesco, Procter & Gamble
Long-known for his appearance as the lovable Barry Taylor in Auf Wiedersehen, Pet in the early 80s, but now also as one of the stars of the BBC's acclaimed drama The Street, Spall has successfully supplemented his acting income with some voiceover work for Daz, Tesco (as have many on this list), Tommy's children's charity and, most recently, Wickes DIY.
4. JULIAN BARRATT
Credits: Martini, More Th>n, Directgov
The Mighty Boosh actor is a relatively recent addition to the world of voiceovers, but he's making up for lost time with a series of ads for More Th>n - five different spots this year alone - and as the voice on an ad that broke early this year for the government information service Directgov, called "help when you need it, in one place".
5. PAUL MERTON
Credits: Direct Line, Phones4U, WH Smith, Energy Savings Trust, Premier Foods, Selftrade.co.uk
The voiceover sidekick to Stephen Fry in this year's series of Direct Line ads has had quite a long break from commercials until recently. He used to be very popular though, voicing ads for Phones4U, Homepride sauces and the Energy Savings Trust, before taking a break in the mid-2000s.
6. BEN MILLER
Credit: PG Tips
A high entry on the list due simply to the fact that Miller, the co-creator of The Armstrong And Miller Show, is the voice of Monkey in the PG Tips ads - who would have thought it? Outside of that, though, he's not as ubiquitous as some, with only one other credit, for the National Year of Reading, to his name.
7. JULIE WALTERS
Credits: Lloyds TSB, Tesco, WH Smith
Walters has long been a favourite with agencies, and has starred in person in ads for Nintendo, the Government's fire safety campaign, Bisto and Asda. More recently, though, she has also used just her voice in quite a few ads for Tesco, as well as a WH Smith spot and the Lloyds TSB "animated train" ad.
8. CAROLINE QUENTIN
Credits: Happy Eggs, Tesco, Seven Seas, Meltus, Colgate, Safeway, Kodak
Quentin, the former star of Men Behaving Badly, who has just returned to TV screens in a new series of Blue Murder, was enormously popular as a voiceover artist in the 90s, with several ads to her name. Recently, however, she's dropped off the radar a bit, with just an ad for Tesco and a recent spot for the free-range food company Happy Eggs to add to her reel.
9. GRAHAM NORTON
Credits: Littlewoods, Talking Pages, Tesco
Norton's brand of cheeky Irish chappie is popular with advertisers, particularly those trying to sell food products: he's voiced ads for Colman's sauces and San Marco Pizza, before returning this year as one of a number of celebrities used by Tesco.
10. JAMES NESBITT
Credits: Ford, Asda, Tesco
After gracing TV screens as the star of ads for Yellow Pages, Nestle Cheerios and the National Lottery, the Cold Feet actor has fallen down the ad rankings. He still merits a mention, though, with voiceovers for Tesco and, most recently, on Ford's "kinetic design" TV spot.