By Cade Metz. From  Wired.

In Africa, more than 100 million people are using Facebook, but they don’t use it quite like people do in the U.S., Mark Zuckerberg and the company announced today.

Eighty percent of those 100 million Africans go to Facebook via mobile phones, and many of those phones are very different from iPhones with 4G wireless connections and large touchscreens now common in the U.S.

In Africa, many people use feature phones — cheaper devices with small screens that provide a limited access online services. The feature phones depend on slow cellular services that charge by the megabyte. Users are extremely careful about how much data they send and receive.

That may not sound viable for online advertising, Facebook’s main source of revenue. But Brendan Sullivan says otherwise. He’s part of a Facebook team that’s exploring new kinds of advertising that could allow businesses to reach people in emerging markets where Internet technology is limited, including not just Africa but also India, Brazil, Argentina and Indonesia.

“We’re seeing a ton of user growth, especially on mobile, in these different regions,” Sullivan says, “and we realize we have a huge opportunity to help marketers better connect with these people.” In some cases, these new-age ads are targeted to the particular speeds of wireless service, and in others, they behave in ways that don’t even use online data.

The company’s work in this area could also show how other online operations can pull added revenue from such regions. In these emerging markets, Facebook is completing with a simpler breed of social networking service that’s better suited to low-end mobile phones—this is one of the reasons that the company acquired the messaging app, WhatsApp, which is extremely popular in certain foreign countries—and on the surface, these services also seem ill-suited to advertising. But initial tests by the company indicate, there are ways of running viable ads in extremely constrained situations.

In India, for instance, Facebook is letting businesses run ad campaigns that behave like missed phone calls. Across the country, Sullivan explains, many people use missed calls to send messages without racking up charges on their wireless data plans. It’s a bit like how people once used collect calls to send messages here in the States: They’ll call a friend or family member and immediately hang up, and this will represent some pre-determined signal, such as “I’m waiting for you outside” or “call me back.” So, Facebook is now offering “missed call” ad campaigns.

When users see one of these ads and click on it, they send a missed call to the advertiser. The advertiser can then respond with a call that delivers certain information or services, such as a cricket score or a product offer—and the user doesn’t eat into his wireless data plan. According to Sullivan, this mimics billboard ad campaigns in India, in which companies arrange for roadside signs that promise services if you send a “missed call” to a certain phone number.

According to Facebook, tests of its “missed call” ad unit have already proven successful in India, and the plan is to roll out similar technology in South Africa and beyond. In similar fashion, the company is also letting advertisers target particular ads to particular speeds of wireless connections, another effort to hone campaigns in places with limited infrastructure.

Sullivan declines to discuss other ways that Facebook could drive ads on more limited phones and through more limited data connections, but he does say that Facebook is constantly exploring new ways of delivering ads that suit particular regions. In South Africa, for instance, the missed call ads may respond with SMS text messages rather than another phone call, because this is more in tune with the way people use their devices in the country. “As we think through these things and expand them,” Sullivan says, “we’re making sure we’re tweaking them in a way that makes sense for each individual market and functions properly under the constraints of the way people behavior there.”

Read more at Wired.