IDC says Apple Watch sales are tanking, but Apple CEO Tim Cook says that’s not so. In fact, he says Apple Watch sales are going strong and the company is on track for a record quarter.

Yesterday, IDC released a report saying Apple Watch sales are down more than 70% year-over-year. The research firm estimated Apple sold 3.9 million smartwatches during its third quarter last year, and this year that number dropped to 1.1 million.

Mr. Cook responded to the IDC report telling Reuters,

Sales growth is off the charts. In fact, during the first week of holiday shopping, our sell-through of Apple Watch was greater than any week in the product’s history. And as we expected, we’re on track for the best quarter ever for Apple Watch.

That doesn’t fit with IDC’s numbers, which isn’t too surprising considering Apple doesn’t share Apple Watch sales figures. Instead, Apple is pulling a page from Amazon’s book—the company never says how many Kindle ebook readers it sells—and keeping the sales numbers secret.

Amazon hasn’t ever offered concrete sales numbers for its Kindle ebook reader line and instead shows slick charts with climbing bars. The implication is that Kindle sales are higher each quarter without any numbers or real basis for comparison.

IDC’s Numbers Game

That leaves IDC and other analysis firms to cobble together their own systems for estimating Apple Watch sales. The numbers they come up with are compiled from a variety of sources such as shopper surveys and retailer data, painting a partial picture of Apple’s sales without an easy way to verify their conclusions.

While analysis firms don’t have an easy way to verify their conclusions, they also don’t have a way to verify Mr. Cook’s statement. In essence, we’re left having to accept what he said as fact, or assume he’s covering up weak quarterly sales.

If Apple Watch sales really are tanking we’ll eventually know when suppliers report multiple quarters where the company cuts parts orders, or if it’s quietly dropped from the product lineup.

Truth in Numbers

IDC is also looking at sales from the quarter before Apple Watch Series 2 was shipping, so it’s possible their numbers are right and Apple’s record breaking proclamation is true, too. Apple Watch buyers holding out for the Series 2 launch may have pushed sales numbers down ahead of the new models, then bumped them back up after the rollout.

Mr. Cook hinted that sales are just fine adding, “Our data shows that Apple Watch is doing great and looks to be one of the most popular holiday gifts this year.”

Still, that doesn’t give us anything more than the idea that sales are better than they were. Without a basis for comparison, there isn’t any way of knowing if Mr. Cook is talking about thousands of watches, or millions.

Apple made it clear before the original Apple Watch shipped nearly two years ago that the sales numbers wouldn’t be broken out. That hasn’t changed with the Apple Watch Series 2 launch this year, and it won’t likely change any time soon.