Steve Jobs said, “This is really hot,” when he unveiled the iPhone 4 at his Worldwide Developers Conference last month. He wasn’t joking.

It took Apple 72 days to sell a million of their original iPhone when it launched in 2007. Last year, the iPhone 3GS sold a million units in three days, a benchmark it took the iPad took 28 days to achieve. But all these look positively lethargic compared to the iPhone 4 and Apple’s most successful launch in its history: they’ve sold over 1.7 million phones in just three days since its release on June 24.

Estimates for Q3 claim sales of 10.2 million units, rising to 12.2 million for Q4.

The really interesting thing is that 77% of those early sales were to existing iPhone owners. Over three-quarters of sales are to folks who are upgrading! That’s the very definition of a want, not a need.

As Seth Godin might say, seek out committed customers and harvest a tribe by finding/making products for them. Inspire and reship.

Steve Jobs is the ultimate tribe leader. Love him or loath him, make no mistake you’re watching the Pied Piper of tech, folks.

Image from Wired magazine.