Apple's Tim Cook shows the incredible growth rate of the iPad

Do you know how many iPads have been sold since the brand's inception just a couple years ago? Tim Cook does, and he revealed at today's Goldman Sachs Technology and Internet Conference that the number is around 55 million. It took three years for the iPhone to sell that many units, and a whopping 22 years before that many Mac computers were sold.

Cook drew the same kind of conclusion that any casual observer could have – although the iPad was the first device of its kind to the market, it came fully backed with all kinds of support and content from the products that preceded it. "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," Cook said during his speech.

Today's event has been one of the biggest tests for Cook since he took over Jobs as Apple CEO last year. He has yet to truly demonstrate his showmanship, but today he has managed to make headlines about his firm stance against unsanitary and unsafe work conditions overseas, and his ability to make the numbers dance just like his predecessor did. The iPad continues to grow and thrive, and more importantly, to innovate. The iPad 3 will be a real test of whether that level of innovation can continue.