MENLO PARK, Calif. — In just eight years, Facebook has signed up more than half the world's Internet population.
Now it's going after the rest.
Facebook is parachuting into market after market to take on homegrown social networks by currying favor with the locals and venturing where many people have spotty — if any — access to the Internet.
In Japan, it lets users list their blood types, which the Japanese think give insight into personality and temperament, much like astrological signs in the Western world. In Africa, Facebook markets a stripped-down, text-only version of its service that works on low-tech mobile phones.
International growth is crucial to maintain its dominance as the world's largest social network. The company's scorching pace of growth has cooled especially in the United States.
"We're not a company that is just trying to add more people," said Chris Cox, Facebook's vice president of product. "What we are trying to do is build a service that everyone in the world can use."
But overseas growth that once seemed to come so easily is slower now. Facebook has saturated most major markets around the globe. Eight out of 10 Facebook users are outside of the United States.
"I don't think that Facebook has a chance of attracting another billion users," Wedbush Securities analyst Michael Pachter said.
Inside Facebook's Menlo Park headquarters is a small army out to prove naysayers wrong. Naomi Gleit is the soft-spoken, headstrong 29-year-old product manager in charge of growth. She says Facebook's future is on mobile devices, the medium by which most people will experience the Web in coming years. Facebook now works on more than 2,500 different phones, helping to gain a foothold in emerging markets. And it is forging relationships with mobile phone operators around the world.
"We originally built a product for ourselves," Gleit said. "This is different. Now we need to understand the experience of users who are not like us."
Analysts say Facebook already has established an impressive track record of uprooting entrenched competitors. In Britain, it displaced the dominant social network Bebo, forcing AOL to sell it at a huge loss. In Germany, Facebook overtook the homegrown StudiVZ. Facebook even broke Google social network Orkut's stranglehold on Brazil and India.
Facebook's toughest challenge by far is that it's cut off from a third of the world's population. The Chinese government, which censors most major U.S. social media websites, has blocked Facebook since 2009.
Facebook founder Mark Zuckerberg has said he would like to find a way to enter China, but even with the recent leadership change there — ushering in the Chinese Communist Party's first new chief in the social media era — most analysts say it's unlikely.
Many investors are far more interested in how Facebook plans to cash in on the users it has than how it plans to sign up more of them, especially in poorer parts of the world where it will be much harder for Facebook to make money.
"Does getting to 2 billion users matter? The answer is no," Pivotal Research analyst Brian Wieser said.
Gleit says growth isn't just a numbers game. Her team focuses on building products that encourage users to be more active on Facebook and spend more time there.
"I have this deep faith in the power of the vision and in the impact we can have," she said. "We still haven't achieved anything near what I think we can."