London, May 22 (IANS): Sperm banks often use images and phrases associated with masculinity to procure sperm for free, new research has found.

"It's interesting that sperm banks are able to procure sperm for free as long as they sell it as a way to affirm the masculinity of donors, especially in today's context when the notion of masculinity is constantly challenged," said study lead author Laetitia Mimoun, Professor at the University of London.

Globally, the sperm donation industry is valued at over $3.5 billion.

After analysing marketing strategies of sperm banks in the UK and Australia, the research team found they relied on masculine archetypes to create value for a commodity they couldn't buy legally.

"This is to say if you give your sperm you are a real man and you are better than all the other men who cannot do so for whatever reason," Mimoun said.

To overcome regulatory constraints and increase donor numbers, sperm banks in the UK and Australia began to market the act of donating sperm as a confirmation of masculinity. This strategy relied on two archetypes of masculinity -- the 'soldier' serving their country and the 'everyday hero' saving a damsel in distress, said Mimoun.

The researchers found campaigns employing the everyday hero archetype sometimes used hyper-sexualised or romanticised images of men to intensify their appeal.

Examples of this are found in campaign posters showing athletically built men in swimming trunks or underpants, but also in videos depicting men cooking barbecues or handing out roses to women.

The use of these marketing strategies had significant impacts on the sperm donation industries in both the UK and Australia, Mimoun said.

The study was published in the journal Marketing Theory.