Sales of Earl Grey tea at a Belsize Park cafe have apparently rocketed due to subliminal messages from a nearby poster for the movie Fifty Shades of Grey.

Ham & High: Does this Fifty Shades of Grey film poster hold a subliminal message?Does this Fifty Shades of Grey film poster hold a subliminal message? (Image: Archant)

A large advert for Sam Taylor Johnson’s film adaptation of E L James’ erotic novel on a bus stop in England’s Lane is thought to have driven sales of the tea blend at nearby Guccino’s coffee shop.

Amerigo Gucci Di Amoi, owner of the Italian cafe, said: “People get affected by advertisements and the media. The name ‘grey’ was in the mind of people instantly, and we have had really massive sales of Earl Grey.”

Belsize’s cafe culture is more usually linked with coffee lovers but the tea blend, with its distinctive citrus flavour and aroma, has seen a renaissance in recent weeks.

The cafe has sold about 25 cups daily, compared to just one or two before the poster was in place.

It’s often said that sex sells but can customers really have Earl Grey on their minds because of a film poster?

On September 12, 1957, at a studio in New York, market researcher James Vicary astonished assembled reporters when he announced he had repeatedly flashed the slogans “Drink Coca-Cola” and “Eat popcorn” throughout a movie, too fast for conscious perception.

As a result he claimed sales of popcorn has risen 18.1 per cent and coke by 57.7 per cent. Subliminal advertising, he declared, was born.

More recent research in strict laboratory conditions carried out by a team of experimental social psychologists at the University of Utrecht in 2006 suggested that subliminal advertising was only effective with products that people knew of and somewhat liked.

Advertising expert and director of commercials Theo Delaney said it is not inconceivable that the movie billboard in England’s Lane has had a similar effect.

He added: “But my experience as an advertising person is that most subliminal advertising is completely spurious.”

However, the founder of film production company Hotspur&Argyle, of Park Road, Crouch End, added: “It is possible this may have happened. There may be something in the typeface of the poster because it isn’t miles away from the packaging of Earl Grey tea.”

The Fifty Shades of Grey trilogy, which follows billionaire tycoon Christian Grey’s kinky S&M seduction of literature student Anastasia Steele, has become a global phenomenon, selling more than 100million copies worldwide since it was published in 2011.

The film adaptation, which premiered on Valentine’s Day, is expected to rake in $100million at the box office.

The run on Earl Grey in Belsize may be more of a flash in a teacup as the poster has now been removed from the bus stop.