Based on O2′s last quarter earnings report, the iPhone is not only O2′s fastest selling device, is not only setting new records for customer satisfaction, but helped contribute towards a 9.5% increase for the last quarter 2007.

In addition to Apple’s debut mobile device having the lowest return rate among O2′s lineup, it also drove a whopping 30% more revenue per user than the carrier’s average, and helped add 483,000 customers and 276,000 new contracts (roughly 60% of which were nicked from the competition).

Impressive, innit?

But is it enough to help shore up what some see as Apple’s diminished leverage with international carriers, especially with companies like China Mobile which boast hundreds of thousands of unlocked units already on their networks? We’ll see…