Scientists found that feminine charm does indeed have economic benefits and can increase success rates in negotiations with both men and women by as much as a third. 

The findings from the first academic study of its kind shows that women who flirt while negotiating the price of a car can get a considerable discount at around 20 percent off the original price.

However, researchers said that the technique needed to be done with the right balance between flirtation and friendliness because women who come off as being too straightforwardly friendly actually lose out more.

Researchers from the University of California, Berkeley, and the London School of Economics conducted a series of experiments and scenarios to measure the advantages and disadvantages of feminine charm in negotiations.

They found while that feminine charm, employed with the right combination of warmth, friendliness, playfulness, flattery and sexiness, effectively deducted the price of a car by a fifth of the price.

In one experiment researchers asked about 100 men and women to imagine that they were selling a car worth £750 ($1200) to a potential female buyer in which researchers had provided them with a written description.

Half of the participants received a description of a woman who flirted through the negotiation by looking the seller up and down, leaning forward and touching the seller's arm, flattering the seller and winking when asking for his or her best price, while the other half read a description of a much more business-like transaction.

Researchers found that flirtatious ‘buyers’ were offered significantly better deals, but only if the seller was a man, and that women who were described as being flirtatious in the written descriptions ended up with a price that was on average 20 percent lower than the no-nonsense ones, according to the study published in the journal Personality and Social Psychology Bulletin.

However the flirtation technique backfired when the women were too friendly or when the seller was a woman.  Flirtatious women actually got worse deals from female sellers, which may be because female sellers got the balance wrong.

Lead researcher Dr. Laura Kray said that women who were perceived as being too friendly and caring may also be thought of as easy prey.

"They are seen as pushovers; as caring solely about satisfying other people's interest. We found that flirtation, on the other hand, conveys assertiveness and power, from someone who is also concerned about satisfying their own interests," Kray said, according to The Independent.

"When perceived as flirtatiousness, female negotiators received better offers, but when perceived as friendliness, female negotiators negotiated worse deals," researchers wrote in the study. "This is consistent with the finding that warmth signals a lack of competitiveness, making friendliness an economic liability in a negotiation."