More than half of the population in Brazil now belongs to “class C”, which became the largest slice of Brazil’s classic “social pyramid” for the first time this past year.

Known as the digital middle class, these Brazilians made up 42 percent of the country’s Internet population in 2010, and are highly coveted by digital marketers, despite their average monthly income being only US$581.

This historic shift has forced Brazilian brands and marketers to figure out how to engage 101 million people to whom they never really had to pay attention before.

It’s clear that the “social pyramid” traditionally used to describe Brazil’s social structure no longer works. Today, a diamond is more accurate. In 2010 alone, 19 million Brazilians “graduated” from classes D and E to Class C.

Social media nation

An impressive 45 percent of class C Brazilians are active on social media. Brands, therefore, have focused their marketing efforts on channels such as YouTube, MSN Messenger, Twitter and Orkut, the Google-owned social network that still trumps Facebook in Brazil.

Popular chocolate brand Lacta, for example, partnered with Orkut on Fazendinha, Brazil’s answer to Facebook’s Farmville game (the name literally translates as “little farm”). When players plant a cacao seed on their virtual farm, the seed grows into a tree that produces MiniBis, Lacta’s new chocolate snack.

These social networks have also given brands access to a previously elusive demographic: middle class women. According to research, 83 percent of class C women access the Internet on a daily basis, and 40 percent of them spend more than two hours a day on social networks.

In order to engage this underserved market, popular Brazilian clothing chain Marisa launched a flashy new website that includes a virtual changing room where shoppers can “try on” clothes on a variety of body types.

Almost half of the Brazilians who use social media belong to Class C, and the vast majority of this “digital middle class” are female.

Different market, different rules

Brazilian brands have learned that the products and strategies they’ve used to reach class A and B consumers can’t simply be “pushed down” to class C.

This new middle class is, after all, making the transition from a very different economic reality in which a can of condensed milk was considered a luxury item to be offered as a gift on special occasions.

Brazil’s emerging consumers will be loyal to brands and products that cater to their unique needs and norms. Sales at the Casas Bahia retail chain skyrocketed after the brand figured out that class C customers loved furniture with mirrored doors because it made their small homes appear bigger.

And since many class C customers live in isolated areas where electronic products such as mobile phones are essential, Casas Bahia added a video series to its shopping website to explain in plain language how to use these unfamiliar items.

Class C-targeted ads also tend to be more didactic and direct. Most middle class Brazilians access the Internet from pay-by-the-hour Internet cafés (LAN houses) and don’t have time to ponder the pros and cons of buying a product while surfing on the clock.

With this reality in mind, department store chain Ponto Frio, one of the largest in the country, has added video and 3-D presentations on its website to reel in customers.

Class warfare goes digital

If wider access to credit lines over the past decade is largely responsible for allowing class C to participate in the economy, Orkut gets credit for putting class C on an even social footing, at least online.

About half of Orkut’s Brazilian users come from the digital middle class. Meanwhile, the upper classes are quietly fleeing to rival Facebook to escape Orkut’s rapid “favelization,” a term commonly used to describe the influx of lower income users.

Some things change more quickly than others.