iPad 2 face downAfter hitting shelves in 2010, Apple has managed to tally 55 million iPads shipped, amassing that figure in only seven short quarters. Who would’ve thought the device would be so popular? Certainly not Apple, admitted CEO Tim Cook at a Goldman Sachs conference today. In addition to addressing growing labor concerns, Cook shared his insight on why he believes the iPad has been so popular, specifically highlighting products that came before it.

The pace of innovation around iPad is absolutely incredible, Cook said. We’ve gone from iPad 1 to iPad 2 in very short order, and the ecosystem around it is clearly thriving. The reason the iPad’s ramp has been so large in my view is that the iPad has stood on the shoulders of everything that came before it — the iTunes store, the iPhone. People trained on these products so by the time the iPad launched it was intuitive to use. I gave one to my mother and she knew how to use it, like this, just from watching the commercial.

To comprehend how quickly the consumer market has accepted the iPad, Cook offered up some staggering figures:

55 million iPads shipped is something no one would have guessed, including us. It took us 22 years to sell 55 million Macs. It took 5 years to sell 55 million iPods. It took three years for us to ship that many iPhones. The trajectory is off the charts.

With the iPad 3 supposedly less than a month away, and even possibly an 8-inch iteration slated for the future, the product’s trajectory certainly looks to be headed far, far off the charts, as Cook suggests.

[via AllThingsD, Cult Of Mac]