China Unicom's 140 million subscribers make it the second largest carrier in the country, only topped by China Mobile, which has 460 million customers. Interestingly, Marshall noted only about half of China Unicom's customers are pre-paid, compared to 80% of China Mobile's.
Naturally, pre-paid customers are of little use to Apple, and the number of post-paid customers the two companies have are on a similar plane. China Unicom has about 70 million post-paid customers, and China Mobile has around 92 million.
China Unicom has been adamantly building its 3G network -- an obvious requisite to host the iPhone. The carrier will begin shipping iPhones in the fourth quarter of this year. On a side note, unconfirmed reports have claimed that the Chinese iPhone will lack Wi-Fi capabilities.