NEW DELHI: Facebook is testing 'missed call' ads in India as it seeks to take advantage of a popular mobile marketing format that has proved particularly successful for some leading brands.

Users of the social networking site can click a button that activates a call to a brand advertiser, immediately hangs up and then receives a return call which can deliver pre-recorded audio messages about everything from sponsored cricket scores to information about shopping discounts. This approach minimises data charges for the user and also works for feature phones which remain a majority in the country.

The potential of such ads was highlighted in recent tests for Garnier Men, the L'Oreal-owned haircare product, during the India Premier League. Users were offered a chance to meet players and win tickets as well as a Flipkart link to purchase products.

Facebook reported that 16 times more calls were generated from the Facebook missed call ad unit than all other digital and print media combined, and its sales rose a claimed two and a half times year on year.

Hindustan Unilever has also successfully used missed-call activations to create category and brand awareness in rural 'media dark' areas, where illiteracy and an erratic electricity supply hampered more traditional marketing strategies.

A missed-call campaign for its Active Wheel detergent brand developed into the award-winning Kan Khajura Tesan which operates as an on-demand entertainment channel – callers get 15-minute programming blocks interrupted every few minutes by advertising – and claims to be the most popular radio station in two states.

Visiting India, CEO Sheryl Sandberg said the service would be rolled out in other developing markets, such as Indonesia and Brazil.

"We really want to invest here because the returns are so great both for our local and global business," she said in remarks reported by Livemint. She noted that the site's US users represented large portion of the US population. "The 100 million that we have in India do not represent a large portion of the Indian population, which means there's such huge opportunity for growth here," she stated.

Data sourced from Livemint, Indiantelevision.com; additional content by Warc staff