Beyond recent news, there's got to be something related to the length of time people are able to use a Mac and have it be very viable. I'm getting 5-7 years from any I've purchased, vs. 2-4 for most of the Windows machines I had been purchasing prior to getting on the Mac train. While I think the Windows machines have upped the ante on that a bit, at least from what I hear anecdotally, you can likely track some of these sales to seasonality, new products, etc. and get a legit handle on how sales are truly going.

Which, funny enough, is what we've been saying about PC's for years but everybody discounts that and assumes PC's are just being decimated by phones and tablets.

I bought my Lenovo developer laptop in 2014. It now runs Windows 10 and is even snappier than when it ran Windows 7.