Apple's iPad business is shrinking like crazy and the iPad Pro couldn't save it

On Tuesday, Apple announced that it sold 16.1 million iPad tablets in the holiday shopping quarter of 2015.

In the same period of 2014, though, it sold 24.4 million. That's a 25% dip in sales, with an accordant 21% revenue dip, by Apple's own math.

That's already pretty bad. It's made worse by the fact that the last quarter also saw the release of the brand-new Apple iPad Pro, which launched in November.

In many ways, the iPad Pro represents what the company sees as the future of computing: A keyboard-toting giant of a tablet powered by the App Store and all of Apple's other services.

But the reception to the iPad Pro was lukewarm. The general consensus is that it's a fine, if huge, tablet, but a lousy replacement for a laptop - no matter what CEO Tim Cook says. The popularity of larger-screen iPhones could also be eating into iPad sales.

Now, even with the iPad Pro's late start in the quarter, we see that consumers didn't think it was especially worth putting on their Christmas shopping lists. That's a problem, given that iPad owners tend to hold on to their devices much longer before trading it in for a new model, compared with the iPhone.

The iPad Pro couldn't buck that trend. And so, the Apple iPad business continues to shrink. If a brand-new iPad couldn't save it, who, or what, can?