I spotted the chart above via this post at Daring Fireball. John Gruber had this to say about it:
If you asked me what the most underrated aspect of Apple is today, I’d say it’s the speed at which iPad sales have grown. The iPhone took off fast, but the iPad has taken off way, way faster. I suspect many Apple watchers consider the iPad an iPhone-like success — but it’s far bigger.
Although I was aware that the iPad’s first year sales numbers were at a record breaking pace, I had no idea how far ahead it is of the sales trajectory for the iPod and iPhone. That’s very impressive.