In a rare TV interview, Tim Cook described this week’s launch of the iPhone on China Mobile as “a watershed day” for the company. While the soft-spoken Apple CEO is noted for the humbleness with which he speaks, it’s hard to imagine him describing Apple as being “honored” to do business with many other companies.

I’m so honored to be doing business with … China Mobile. It’s a huge announcement…we’re incredibly impressed with them, we have deep respect for them, and have had from the very first discussion that we’ve had together” … 

It had been suggested that Apple found itself in an unusually weak position when negotiating with the carrier, and may have had to make significant concessions to seal the deal.

Neither Cook nor China Mobile’s chairman Xi Guohua would be drawn on sales expectations, but China Mobile did say that it had received 1.2 million pre-orders as of Monday. It was reported yesterday that Apple had shipped 1.4 million iPhone 5s handsets to China ahead of Friday’s launch – with no word on 5c numbers.

Analyst estimates of the likely value of the deal have varied wildly. Cook had previously spoken of the deal as “only the beginning” of its cooperation with the carrier, saying there were “a lot more things our companies can do together in the future.”

The iPhone 5s and 5c have been officially sold by both China Unicom and China Telecom since the handsets were launched last year, but China Mobile’s network dwarfs both. Both smaller carriers have cut their pricing in a bid to compete.

Apple’s stock price initially fell when the launch did not take place on 18th December as had been predicted, then rose again when the deal was finally officially confirmed.