EVER since Facebook made its stockmarket debut on May 18th, its new shareholders have had ample reason to grumble. The company’s shares have been trading for much less than the $38 at which they were first offered. The social-networking giant’s first quarterly results as a public company, unveiled on July 26th, did little to cheer shareholders up.

The numbers Facebook reported were in fact far from shabby. In the three months to June revenues were 32% higher than a year earlier, at $1.18 billion, much as expected. Facebook also boasted an increase of 29% in its number of monthly active users, to an astonishing 955m. Against that, the company made a loss of $157m, largely because of a huge rise in share-based compensation costs. And Facebook gave no guidance to its future prospects. The market had not cut Apple any slack two days earlier, despite increases in revenue and profit of more than 20%; it cut Facebook none now. The share price fell by more than 10% in after-hours trading, to below $24, a record low, having already lost 8.5% during the day.

The main way in which Facebook turns membership into money is through advertising: 84% of its revenue comes from ads. For advertising budgets, pointed out Brian Wieser of Pivotal Research Group in a note earlier this week, country-by-country numbers matter more than the global total. In some countries, notably America, which produces half its revenue, Facebook may have reached saturation: comScore, a research firm, reckons that it had 159.8m American members in June, 1.1m fewer than a year earlier. But “there is still no other satisfactory [social media] provider for most marketers”, Mr Wieser wrote. Twitter, which has the next widest reach, attracted 41.1m visitors last month. People also spent far longer on Facebook than on any rival medium.

However, there is room for doubt about the effectiveness of Facebook ads—and especially about Facebook’s ability to put moneyspinning ads on mobile devices. People are checking Facebook more and more often on phones and tablets, rather than on desktop computers, yet making suitable ads is harder for smaller screens. The company is yet to show that it can nail this, although Sheryl Sandberg, Facebook’s chief operating officer, told analysts that “sponsored stories” (posts saying that a friend has “liked” an advertiser or its product) are bringing in $1m a day, half of it via mobile devices.