In just four days, iTunes grabbed 27.78 per cent (by Yen value) of what existing music download services sold in the first six months of 2005, Japan Today suggests.
Citing figures from the Recording Industry Association of Japan (RIAJ), Japan Today reports that music download sales to computers were worth 540 million Yen (£2.71 million) in the January to June period.
iTunes Music Store Japan sold one million tracks in just four days after its launch last week. With 90 per cent of its available tracks sold at 150 Yen (75p), the news indicates Apple to have already reached sales valued at 150 million Yen or more - in four days.
This represents a significant fraction (27.78 per cent) in revenue terms of computer download sales generated in the first six months of 2005 in Japan before iTunes launched.
However, event this achievement is dwarfed in comparison to the activity around mobile phone music downloads in the territory, particularly of ringtones, the report explains.
RIAJ data shows 96 per cent of the 14.16 billion (£71.2 million) Yen value of downloads was acquired using a mobile phone, with computer downloads accounting for a relatively paltry 540 million Yen.
The country has already tuned-in to 3G services. Services such as iMode have become traveller's essentials in Japan.
All currency exchange calculations conducted Friday August 12 at 12pm.