Facebook, the world's biggest social network, had 67m monthly active members in Brazil by December last year, an annual increase of 81%, making it the service's second largest market behind the US.
Alexandre Hohagen, vice president of Facebook's Latin American arm, argued Brazilian users talked almost incessantly about TV programmes, sport and news on its site, reflecting their offline behaviour.
"It's common for someone to start talking to you in the elevator or in a restaurant just to start a conversation," he told the Wall Street Journal. "I think our culture … really makes people much more open to include and connect to friends."
Hohagen further suggested that ecommerce habits are developing rapidly, with web users happy to purchase anything "from a book to a car online, which is not very common in other countries."
As shown by Warc's recent Seriously Social report, marketers are also making more use of this channel to reach consumers, with Audi, the automaker, and GRAACC, the charity, showing this trend in action.
Further, Brazil was the biggest market for YouTube beyond the United States by the close of last year in terms of unique visitors, as well as being one of the Google-owned platform's five top revenue sources.
"Brazilians have this passion to share information, to share pictures," Álvaro Paes de Barros, director of YouTube content partnerships, Latin America, said.
As the FIFA World Cup football tournament will be held in Brazil in 2014, as will the Olympic Games in 2016, there is "a lot of curiosity about Brazil" at the international level, he added.
Twitter, the microblog, has established a presence in São Paulo, and is recruiting sales, marketing and business development staff. By contrast, it works through local sales representatives in other rapidly-growing outlets like Argentina, Colombia and Chile.
"The size of the market made it important to have our own presence," said Shailesh Rao, Twitter's vice president, international revenue growth.
According to comScore, the research group, social network users in Argentina logged the most hours on these sites in November 2012, on 9.8 hours, ahead of Brazil on 9.7 hours and Russia on 9.6 hours.
Figures from eMarketer, the insights provider, have also suggested that online adspend should double to $4bn in the coming four years.
Currently, however, brand owners only commit 10.6% of their budgets to digital, versus a global average of 19.8%, the research firm has found.
Data sourced from Wall Street Journal; additional content by Warc staff