Political parties have spent an estimated $8.47 million (Rs 50 crore) on radio advertising in the build up to India’s general elections.

The longest vote in the country’s history began on April 7 and runs until May 12 in nine phases.

Local media reports that revenues from political advertising have increased by more than 500 percent since the last national poll in 2009. 

Many pundits put this down to the low cost of radio campaigns compared to running TV spots.

But despite this, the largest share of budgets is still going on TV while another growth sector is digital and mobile.

One of India’s largest radio networks BIG FM told Asia Radio Today that the four main political parties as well as individual candidates were using the broadcaster’s ad inventory in several territories.

A spokesperson for the company estimated that political parties were spending as much as 15 percent of their overall promotion budgets on radio.

Some industry pundits have complained that public broadcaster All India Radio (AIR) receives an unfair share of political advertising budgets, while others accept that AIR reaches many areas not covered by private FM broadcasters

BIG FM told Asia Radio Today the reason why radio had achieved a larger share of political revenues this time:

“Primarily it has allowed the parties to: turnaround communication in a matter of hours, change communication basis the context of the environment, regionalise and localise the communication specific to a language and city/region, create word of mouth awareness and drive high reach – due to the fact that radio is consumed by people through the day in large numbers, the campaigns have been effective,” said a company spokesperson.