Mobile industry consultants Eurotechnology Japan KK estimate that between 75,000 and 125,000 iPhone 3Gs were sold in Japan between the device's release on July 11 and the end of the month. The company describes its methodology in an August 8 message:

• SoftBank Mobile subscribers increased by 158,900 during June 2008, but 215,400 during July 2008.
• Eurotechnology sees no similar large jumps in past data, other than seasonal jumps in March of the years observed (attributable to strong sales before the traditional start of the financial year, school year, and general employment year in April).
• As no other high-profile phones were introduced by SoftBank in July, the month's unusually high subscription increase of 56,500 users can be safely attributed to new iPhone 3G subscribers (including existing SoftBank subscribers adding iPhone as a second phone, or defectors from other carriers).
• The above would not count existing SoftBank subscribers upgrading from an existing phone to iPhone. With no numbers released by SoftBank, Eurotechnology guesses at a number similar to the 56,500 new subscribers – or for simplicity, 100,000 total.
• Assuming a +/-50% margin of error on the number of upgrading subscribers yields a ballpark result of 75,000 - 100,000 iPhone 3Gs sold in Japan during July 2008.

If sales keep up that pace, Eurotechnology estimates between 640,000 - 1 million iPhone 3Gs sold in Japan during 2008. Nice numbers - though still only 1.2 - 2% of all handsets sold in the country for the year.

The Japan iPhone 3G sales numbers are a big piece of guesswork, but it's a rough block to start whittling into useful shape as more data appears. Stay tuned for more –

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