Mac sales take a 12 percent tumble year-over-year as users upgrade less often

The sales decline also outpaces the downturn in the PC industry as a whole. Quarterly sales estimates from Gartner and IDC estimated that PC sales fell at 9.6 and 11.5 percent for the first quarter of the year. The slowdown also surprised analysts from both firms. Earlier this year, they expected Apple to sell around 4.5 million Macs for the first quarter of 2016.

The results marked the second straight quarter year-over-year Mac sales fell, as sales were down slightly during the holiday quarter, too. Before that, Apple enjoyed a streak of growing Mac sales that went all the way back to the fourth quarter of 2013 — a time when most PC makers saw quarterly sales numbers fall year-over-year.

Of course, the sudden slowdown in Mac sales has some wondering why Apple’s luck has run out. The answer could be no different than that of its PC brethren – consumers just don’t see the need to upgrade frequently anymore.

Analysts say there’s no indication of a slowdown in PC-to-Mac conversion, so slower upgrade cycles seem to be the most logical explanation. With PC hardware innovation far outpacing the needs of the software, applications run adequately longer, which in turn gives the consumer less reason to upgrade.

Add to this lack of innovation in Mac OS X itself: it’s largely the same operating system it was at its launch over a decade ago, and refusal by Apple to add compelling new features like touchscreens to its systems provides even less reason to upgrade.

Despite the sales woes, Apple remains optimistic. During its Tuesday earnings call, CEO Tim Cook said Mac sales hit internal expectations, and CFO Luca Maestri noted that it was “a challenging quarter for personal computer sales across the industry.”

What remains to be seen is how much more challenging it will become, for both Apple and PC makers both.