A TELEVISION advertisement in India for a mobile-phone operator opens with four friends staring forlornly at their car’s smashed windshield. “Call the police,” mutters one. His friend whips out a phone, dials for help and promptly hangs up after one ring. Others look at him quizzically. “I’ve given them a missed call,” he says sheepishly. “They’ll call back.” Everyone, incredulous, rolls their eyes in his direction, as the voiceover encourages viewers to switch to the operator’s dirt-cheap call rates. The ad, in good humour, portrays how the missed call has become part of daily life in India. According to one estimate, 65% of India’s 860m mobile subscribers prefer it to a quick call. It is a proxy for a pre-decided short message like “thinking of you” or “call me back”. Missed calls often morph into modern-day Morse codes too. Roadside tea vendors routinely accept dropped calls from nearby mom-and-pop stores as a nudge for service; newspapers use it to urge customers to renew subscriptions; and bank balances can be requested the same way.

The practice dates back over a decade to when exorbitant calling rates forced customers to find a smarter way to communicate. Today, even with some of the lowest call rates in the world, the habit has stuck. It is here that Zipdial, a Bangalore-based outfit, spotted an opportunity to monetise the Indian mobile subscriber’s stinginess.

The start-up offers a new way for advertisers to reach their customers. Brands prominently display a phone number in their ads, urging people to dial it. The call, once made, disconnects automatically after one ring and the caller is sent a text or a voice message informing him of offers and discounts. “Every single Zipdial is like clicking on a link,”says Valerie Wagoner, the firm’s boss. Each missed call signals buying intent and is gold-dust for marketers.

Since 2010, when it was founded, Zipdial has raked in 414m missed calls, which translates to a staggering 375,000 enquiries per day. It currently runs 400-odd marketing campaigns simultaneously and its clients include Fortune 500 firms as well as start-ups. However, the biggest challenge in the first couple of years was to convince companies about the merits of missed-call marketing. Two instances helped.

The first time the service went viral was when it tapped into India’s biggest obsession: cricket. During the 2011 world cup Zipdial relayed cricket scores and updates through text messages in exchange for missed calls. On the day that India played Pakistan Zipdial clocked 4m calls. It then gathered data about callers by asking responses on their gender, age, city etc. The second time Zipdial’s numbers soared was in 2011 during a nationwide anti-corruption campaign led by Anna Hazare. To pledge support for his programme, callers were invited to “Zipdial” a number that flashed on one of the news channels. Alternatively, users also had an option of voting on social-networking sites, Twitter and Facebook. Within a few days Zipdial corralled 4.5m calls, which dwarfed 36,000 Facebook likes and 1,450 retweets.

“We are not selling missed calls,” explains Ms Wagoner, “We are selling consumer engagement through a simple interface”. Analysis of data that are collected from these campaigns is what Zipdial is paid for. Indeed, distinguishing a repeat customer from a first-time caller can help deliver appropriate marketing messages to both. Just like loyalty card programmes can help the advertiser in understanding shoppers' habits, a lot can be derived by mining data about which Zipdial services customers are responding to. Addressing privacy concerns, Zipdial insists that phone numbers are neither sold to advertisers nor spammed.

In April Zipdial launched a service in Sri Lanka and is eyeing South-East Asia next. The strategy in these countries will be different. The Philippines is considered the SMS capital of the world and Indonesia has a high mobile internet population. But the premise of Zipdial’s business idea will continue to revolve around an old concept called permission marketing. This is where the traditional blunderbuss assault of marketing your message is replaced by a more subtle approach of seeking permission from a customer before advancing your wares.