It was pointed out that, in Japan, the iPhone 3GS ranked #1 and #2 (32 GB and 16 GB) almost a month ago because it was the week of the phone’s debut. Even for that, taking the top two spots in a country where the phone was supposed to fail miserably, debut week or not, was a pretty good showing.

Well, now it’s three weeks later. How is the iPhone doing? In week #2, the 32 GB dropped to #2, and the 16GB dropped to #9, seeming to confirm that the iPhone’s popularity was an artifact of the publicized release.

But then, in week #3, the 16GB iPhone stabilized at #9–and the 32 GB iPhone popped back up to #1. In such a competitive marketplace, a debut fad should not act that way. The iPhone is not just #1 as a blip. After 3 weeks, both versions of the phone rate in the top 10. Sharp is the only other maker with more than one handset in the top ten (they have 3, at nos. 2, 5, and 6); the rest of the top ten include single placements from Panasonic, NEC, Sony Ericsson, Casio, and Fujitsu.

Remember, the iPhone was supposed to fail utterly because Japan’s market is saturated with highly advanced smartphones. So, why is the iPhone still #1 after 3 weeks?