Apple reported Monday that its sales in China almost doubled during the December quarter over the year-ago quarter. In a conference call with analysts, the company took the unusual step of breaking out its iPhone numbers for the country (Apple crossed the 200,000 activation mark in early January), and COO Tim Cook said he was pleased with the company's progress in the world's most populous country.

Apple unveiled the iPhone in China in late October, and analysts have been keen to gauge the device's reception in that market, which is the largest market for cell phones on the planet. Because of this, Mr. Cook told analyst Ben Reitzes when asked about China, " We typically do not disclose units by country given the visibility to do so."

As noted above, Apple passed the 200,000 iPhone activation mark in early January, and Mr. Cook said the iPhone was now available in some 1,500 retail locations in China.

He added, "We are very, very focused on the quality of the point of sales and the customer experience; and so we would prefer to move slow because we are building the brand for the long-term. We are very much focused on the long-term in that market because we think there is significant potential there."

He also said that Apple was, "very happy working with China Unicom," the carrier Apple partnered with for the Chinese market.

Analyst Katy Huberty also asked about China, and Apple's pricing approach to emerging markets where income levels are lower than in the U.S.

Mr. Cook said, " I really like what I see so far [in China]. Although the average income is not nearly as high as perhaps the United States and some other western European markets, there is a significant size middle class and up there. I think to do a real deep analysis you have to look not just at the average, but at the distribution of income within these countries."

In what Mr. Cook called the greater China market of China, Taiwan, and Hong Kong, Apple saw revenues triple year over year, which Mr. Cook, "phenomenal by any measure."