In what’s sure to be an announcement that pisses no one off, IBM released data today showing that it has saved between $273 and $543 per user by choosing to deploy Apple Macs instead of IBM PCs. Fletcher Previn, VP of Workplace as a Service at IBM, spoke at the Jamf Nation User Conference, and shared some of the company’s metrics and data. It should be noted that Jamf is an outfit dedicated to supporting Apple products in the field, which makes them a bit less than a neutral source — but IBM would have little reason to lie about its figures and savings.

IBM started allowing employees to choose between Windows and Mac in 2015, according to Previn. “The goal was to deliver a great employee choice program and strive to achieve the best Mac program,” Previn said. The $273 to $543 savings is the expected amount over four years compared with a conventional Windows PC deployment. “And this reflects the best pricing we’ve ever gotten from Microsoft,” Previn added.

With an estimated 90,000 Macs deployed, IBM is actually the largest single business customer for Apple hardware (we’ll pause and let the irony of that sink in). While we doubt anyone is making crazy bonus money by cutting out $543 in IT savings over four years — even for 90K deployments, that’s not a lot of money at the Fortune 500 level — it’s still interesting to see Apple products saving that kind of cash. But here’s the real question that no one seems to be asking: Why does switching to Apple save IBM money?

Last year, Previn gave a bit more detail, claiming that 40% of PC users called the IT help desk, versus just 5% of Mac users. Again, this sounds damning for Microsoft, but the criteria are vague and the reasons behind the problems aren’t given. Does IBM have a better, more robust set of documentation for its Apple users than exists on the PC side? How many of the phone calls to the IBM Help Desk were questions about Windows 10 upgrade notifications, or other issues related to that OS? Do the Mac and PC arms of IBM use different software packages or deployment systems, and is it easier to configure the Mac versions than the PC flavors? Does the hardware in various PC laptops fail more quickly than in Macs, and if so, which types of systems seem to be the worst affected?

These are the sorts of questions I wish more Fortune 500 companies would answer. They’re virtually the only businesses, outside of the manufacturers themselves, who might have large enough sample pools to accurately give data on system failure rates. One of the great perennial questions our readers ask is who makes the most reliable laptop (or in some cases, desktop). The truth is, reviewers and writers like myself don’t really have a better window into that question than average users.

Every now and then, a company like SquareTrade will release a report on laptop failure rates, but the last time the company issued one was in 2009. Microsoft did a paper in 2012 on component failure rates, and Backblaze releases some hard drive-specific data, but none of these are a comprehensive comparison of the PC-versus-Mac ecosystem. (The closest we can get is our sister site PCMag’s yearly Readers’ Choice survey, which includes a section on laptops and desktops.)

These distinctions matter. If the reason only 5% of Mac users call the IBM help desk is because Windows machines are 8x more likely to suffer a hardware failure, that’s information ordinary consumers might want to price into their laptop shopping. If the reason only 5% of Mac users call the IBM help desk is because one of the Windows software packages IBM deploys is less stable than its Mac equivalent, that still may matter to IBM — but it doesn’t have much relevance to you or I.

So how about it, IBM? Care to share a little more information on that old Mac Magic?