When Apple (AAPL 0.52%) launched the iPad back in 2010, then CEO Steve Jobs said the computing world was entering the "post-PC" era, a term Jobs actually used as early as 2007 when talking about the iPhone.

But when the iPad debuted, it seemed evident tablets would kill our clunky computers and, in some ways, they have replaced some traditional computing uses. But four years after the iPad debuted, tablets haven't fully replaced our computers yet -- and Apple's own Mac sales are part of the reason why.
 

Source: Apple.

Steady as a Mac
In the most recent quarter ending in June, Apple's Mac sales topped 4.4 million, an increase of more than 17% year over year. The company generated $5.5 billion from its Macs, driven partially by a bump in sales from its MacBook Air line. In an earnings call, Apple CEO Tim Cook said a $100 price drop on the Air's, along with a faster processor, helped push sales higher.

Cook also said that giving away the Mac OS X software updates away for free helped Mac sales. But growth in China contributed, as well. Mac sales in the region were up 39% year over year.

If the beginning of the post-PC era started when the iPad launched in Apple's fiscal Q3 2010, no one told the Mac division about it.

Here's a look at Apple's fiscal quarterly Mac sales since the iPad launch.



Data source: Statista.

We can see that worldwide Mac sales have been extremely stable since the iPad hit the market, and there've been some quarters of significant spikes.

But aside from strong Macs after the iPad debuted, the most important fact is that Mac revenue came very close to the iPad's. In Q3, Macs generated $5.5 billion in revenue for Apple, compared to the iPad's $5.8 billion.

What to expect going forward
Apple's iPad unit sales dropped 9% in Q3, proving that even Apple isn't immune to slowing tablet growth. After dropping 9.5% in 2013, Gartner says the PC market will see a "relative revival" in 2014, while tablets are experiencing a slowdown compared to 2013.

Ranjit Atwal, a research director at Gartner, wrote in a release earlier this month that, "The next wave of adoption will be driven by lower price points rather than superior functionality." Considering Apple's iPad is focused much more on the latter, the company will face an uphill battle as tablet growth slows.

As The Wall Street Journal recently noted, Mac sales have outpaced PCs in 30 of the past 32 quarters; but investors shouldn't expect future Mac news to be all rosy. Gartner expects notebook and desktop sales to decline 6.7% this year, and 5.3% in 2015. Though Macs are taking a bigger piece of the PC pie, those forecasts could still negatively impact Mac sales going forward. Investors should look to any major changes in the MacBook lineup, like the rumored 12-inch Retina MacBook Air, to make more gains in the PC market.