Thursday, October 13, 2011 at 2:24 pm.

The most amazing thing about Apple is how fast it’s still growing

There are many impressive facets to Apple’s business: Its sheer size, its growth over the past decade, its international growth, its profitability, and how much of it comes from the iOS platform, which only came into existence four years ago.

But the thing that amazes me the most is how fast Apple’s revenue is still growing, even at its current size. Even the pathetically wimpy Street analysts that cover Apple expect its sales to grow 44% this past quarter, on a year-over-year basis. (Apple reports Sept. quarter earnings next Tuesday.)

That rate far exceeds its peers in the tech industry, even those that are significantly smaller. Google, which reports earnings tonight, is expected to post 32% growth. Microsoft, just 7% this past quarter. Amazon (not pictured in chart) is expected to report 45% growth this past quarter, but its sales are less than half of Apple’s.

Revenue growth chart Q3 2011

In an informal flip through the Fortune 500 companies, the only industry that seems to come close to Apple’s current growth — at its size or larger — is the oil business. Chevron, for instance, is twice Apple’s size and is growing at the same rate. Exxon Mobil would break this chart: $121 billion in expected revenue, at a 27% growth clip.

So, how long can Apple keep this up? Will it continue the good fight against the law of large numbers?

The biggest factor is the iPhone, which represents about half of Apple’s sales. Will its new features and pricing help it eat away further at RIM’s market share, and take some from Android? Can it continue to outpace the smartphone market growth as a whole? And will the iPad become the next generation of personal computers, and a really, really big business?

And then, beyond those two, does Apple have a new growth driver in the works, as the iPod business declines and Mac growth slows? That’s what to look for in the next year or two.

Related: The amazing Steve Jobs effect: Apple’s performance before and after Steve’s comeback