Steve Jobs likes to wait for nice round numbers before he announces his milestones, and on Monday Apple hit a big one: the 85,000 apps in the iPhone App Store have now been downloaded more than 2 billion times — a number Jobs described as "staggering."

"The rate of App Store downloads continues to accelerate," he said in a prepared statement, pointing out that more than half a billion apps were downloaded in Apple's fourth fiscal quarter alone.

He's right about the acceleration, but judging from the slope of the curve above, it's not quite as dramatic as he makes it sound.

It took Apple 74 days to rack up these half billion downloads, and 82 days to get the previous half billion.

Put another way, users were downloading apps at the rate of 6.1 million a day between April 23 (when the App Store hit 1 billion) and July 14 (when it hit 1.5 billion), and the rate of 6.7 million a day between July 15 and Sept. 26, a 10% increase.

Impressive, but given how many customers Apple has added in the past quarter, maybe not staggering.

Among the other numbers Apple announced Monday:

• Apple has sold more than 50 million iPhones and iPod touches (up from 37 million in April)
• The App Store is available in 77 countries
• There are 125,000 registered iPhone developers

source: fortune