Apple Watch sales dropped 63% from the holiday quarter

Apple doesn't reveal Apple Watch sales like it does for the iPhone, iPad, and Mac lines.

So our best guess about just how many smartwatches Apple has sold comes from industry research groups, in particular, IDC, whose data is frequently cited by Apple executives.

IDC just came out with its latest wearables estimates, and it has an estimate for first-quarter Apple Watch sales: 1.5 million units shipped.

That's a big drop sequentially from last quarter, in which IDC estimated Apple shipped 4.1 million Apple Watches, although that quarter had the benefit of being a holiday quarter. (And even last quarter's estimate could be seen as disappointing.)

That's a 63.41% drop sequentially. Year-over-year change isn't available because the Apple Watch only went on sale last April.

The Apple Watch hardware hasn't been updated since it was released one year ago, but Apple has refreshed the product with new bands and software. During this past quarter, Apple also dropped the entry-level price for the Apple Watch to $299.

While the Apple Watch is clearly the best-selling smartwatch in the world, blowing out similar smartwatches from Google and Samsung, according to IDC's estimate, both Fitbit and Xiaomi are crushing it with sales of simpler wearables. (Xiaomi, which sells almost exclusively in China, passed Apple this past quarter.)

"Turning to the Apple Watch, unit sales met our expectations in the quarter," Cook said during Apple's most recent earnings call. "For some color on how we think about Apple Watch sales, we expect its seasonality to be similar to the historical seasonality of iPod, which typically generated 40% or more of its annual unit sell-through in the December quarter."

Here's the shipment chart, including basic wearables, like Fitbit:

Here's the chart looking at smartwatches exclusively: