As campaigning for the assembly elections in India’s capital, Delhi, came to a close on Thursday, radio had already emerged a winner in the political battle.

According to the Financial Express, the Delhi radio market, which is worth $58 million (Rs 3.6 billion), is estimated to have earned an additional $3.24 million (Rs 200 million) from political ads by the three main parties –Bharatiya Janata Party (BJP), Aam Aadmi party (AAP) and Congress.

The ad rates for radio spots shot up by 25 to 50 percent in the run-up to the polls with Radio Mirchi, Red FM, Radio City and BIG FM asking for up to $24 (Rs 1500) for each spot, while the rest charged up to $16 (Rs1000), according to a senior media planner.

Delhi has eight private and three government-owned stations and each channel aired 40 to 50 political commercials every day during the campaigning, with a full inventory for more than a month.

Studies have shown that radio has almost 90 percent penetration in Delhi, making it a truly mass medium.

The fact that radio advertising is much cheaper than TV or print has also contributed to its increasing role in political campaigns.