John Gruber at Daring Fireball:
But if Apple gets it into its head that they should only work on iPhone-sized opportunities, it would paralyze the company. In baseball terms, it’s fine for Apple to hit a bunch of singles while waiting for their next home run. According to Apple, they had more watch sales by revenue in 2015 than any company other than Rolex, and Apple’s “Other” category, which is where Watch sales are accounted for, had a near record-breaking holiday quarter three months ago, suggesting strongly that Watch sales were up over the year-ago holiday quarter.
These two facts are both true: Apple Watch sales are a rounding error compared to the iPhone, and Apple Watch is a smash hit compared to traditional watches and other wearable devices.