THE IPHONE IS Apple’s crown jewel. It accounts for most of Apple’s revenue. During its most recent quarter, it sold more iPhones than ever. And yet it’s still not living up to expectations.

From October to December, Apple says it sold 74.8 million iPhones. To which Wall Street responded: meh. (Its oracles expected the company to sell 75.5 million units.)

Apple can confidently expect to see a boost in iPhone sales during the holiday season. Last year, Apple blasted past Wall Street’s expectations by nearly 10 million iPhones (74.4 million units sold versus the expected 65 million). That also happened to be the first full quarter the larger-screened iPhone 6 and 6 Plus were available—and larger screens were what users wanted, both at home and in China.

This year tells a different story. Compared to the same time last year, iPhone sales saw their slowest growth—0.4 percent—since the product was launched in 2007. These days, China’s economy is slowing, and most people who want a smartphone probably already own one.

But the real lesson is that success is relative. Apple revealed today that 1 billion people used its services, including iTunes and its App Store, in the past 90 days. Yes, that includes iPad, Mac, Apple TV and Apple Watch users, too. But the iPhone surely makes up a huge chunk of that base—nearly 75 million in the last three months alone.