According to an internal Microsoft document seen by the Seattle P-I, 56 per cent of Xbox Live users worldwide were paying for Gold subscriptions as of this time last year.
The spreadsheet included projections up to June 2008, and showed the proportion of Live Users with Gold staying steady at between 50 and 60 per cent for more than a year. The proportion was slightly higher in the US (60 versus 56 per cent in February 2008).
A Gold Xbox Live membership allows players to play games online. The free silver membership only allows the use of Microsoft's content download services, such as Xbox Live Arcade and the Video Marketplace.
Microsoft's most recent figures state that there are 17 million Xbox Live members out of a total of 28 million Xbox 360s sold since launch. If the Seattle P-I's figures are still accurate, some 9.5 million people - around 34 per cent of the total number of Xbox 360 owners - are paying Gold members.
If 34 per cent doesn't sound that impressive, consider that they're paying a minimum of USD 50 a year each. Xbox Live Gold could therefore be bringing the software giant some half a billion dollars in annual revenue.
In other words, it's up there with only World of Warcraft in terms of subscription gaming services.
Microsoft wouldn't comment on the specifics of the document, but did confirm to the Seattle P-I that "a majority" of Live users were Gold members, at that the number was always growing.
"We've said before that Xbox Live is experiencing incredible growth; in January we had more new Live members join than any other month in the history of Xbox Live," it said.
"With more than 17 million active members, a majority of whom are paying members, Live is a rich social entertainment and gaming experience that is unmatched in the industry."