New Apple iPhone 6 and 6 Plus officially go on sale

The wait for one of Apple's most anticipated products in years in now over.

The iPhone 6 and 6 Plus officially went on sale this morning. People turned out in record numbers to buy the devices, which CEO Tim Cook called "the biggest advancement in the history of iPhone."

This morning, Cook showed up at the Apple store in Palo Alto, California, where he walked the entire line of fans. He talked to customers, shook hands, took selfies and welcomed Apple loyalists into the store.

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CNBC asked cook about which new iPhone he carries. "Both," he said, "I'm lucky."

Right out of the gate, demand has been strong. The company says pre-orders topped a record 4 million in 24 hours. The next important data point for investors is how many new iPhones Apple sells this first weekend.

In New York, 1,880 people were in line at Apple's flagship store at 8am, waiting to buy the phone. Some analysts expected to see a scarcity as early as this weekend.

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Consumer demand is expected to remain high. Analysts at RBC estimate that Apple could sell 10 million of the new iPhones. That would be a new record, and one million more than the launch last year of the 5s and 5C.

The new phones are bigger at 4.7 (iPhone 6) and 5.5 inches (iPhone 6 Plus), and they're faster, thinner, with improved cameras and longer battery life.