Mark Zuckerberg Talks of Spending, and Facebook Stock Drops

SAN FRANCISCO - The law of large numbers says that a company will grow more slowly the bigger it gets.

Somebody needs to tell that to Facebook.

The company said on Tuesday that third-quarter revenue grew 59 percent from the same period a year earlier, to $3.2 billion. Most of Facebook's revenue comes from advertising, and the company said that two-thirds of those dollars now come from ads on mobile devices, up from half a year ago.

'Our strong results show the shift to mobile is working,' Sheryl Sandberg, Facebook's chief operating officer, said in an interview. 'Our performance is very broad-based. Our growth is across all of our regions.'

Net income in the quarter was $806 million, or 30 cents a share, up 90 percent from the $425 million, or 17 cents a share, it earned a year ago.

Excluding costs related to acquisitions, employee compensation and taxes, Facebook made a profit of $1.15 billion, or 43 cents a share, up 73 percent from last year.

Wall Street analysts expected the company to earn 40 cents a share on that adjusted basis and to post revenue of $3.1 billion.

Facebook's shares were roughly flat in after-hours trading after the release of the results. The company regularly exceeds analysts' financial projections, so the fact that it did so again this time caused few ripples among investors.

The company said it had 1.35 billion monthly users in September, up from 1.32 billion in June, and 64 percent of them used the service daily, up slightly from the second quarter.

Facebook's global user growth, like Twitter's, has been slowing, but that has not troubled Wall Street the way Twitter's slowdown has. The reason is that Facebook, the world's largest social network, is so huge in developed countries that the only markets still open for major expansion are poorer nations, where the immediate prospects for selling ads are dimmer.

Still, that hasn't stopped the company from courting consumers in those markets. Mr. Zuckerberg recently visited India, China, Indonesia, South Korea and Japan to meet government and corporate leaders and promote Facebook's virtues.

'Those travels are really important,' said Ms. Sandberg, who joined Mr. Zuckerberg in Korea. 'More than 80 percent of our users are outside the U.S.'

Besides its international expansion, Facebook is beginning to use its knowledge of its users' interests to sell ads beyond its social network.

A month ago, the company introduced a revamped version of its Atlas ad platform, which now allows marketers to choose the age, gender and other attributes they want to target and have Facebook serve specific ads to them on other websites and mobile apps.

'Facebook Atlas is the biggest thing to take on Google in a long time,' said Jan Rezab, chief executive of Socialbakers, a social media analytics firm.

Mr. Rezab also says he expects Facebook to improve the ability of businesses to aim ads at mobile users based on their current locations - a feature that could be attractive to, say, a pizzeria that wants to reach potential customers at lunch time.

The company has been gaining share in the global market for digital advertising. The research firm eMarketer projects that Facebook will account for 20.4 percent of mobile ad spending and 8 percent of total digital advertising this year.

Investors will be looking for more information about ad sales on Instagram, the photo-sharing service that Facebook acquired in 2012, and about Mr. Zuckerberg's plans for WhatsApp, the messaging service that Facebook finished buying last month for $21.8 billion.

Ms. Sandberg said advertisers were interested in ads that use images, but Facebook is proceeding slowly so as not to upset its users.