[brudgers]

"Microsoft had not released any sales figures for Windows 8 other than saying the company sold 4 million upgrade licenses of the operating system to those with previous versions of Windows during the first three days it was available."

That's 10% of the total in the first three days to existing users.

Including myself.

[dkhenry]

If a month has 30 days then that's also 10% of the time period, or another way of saying it is that sales remained constant over that initial time frame.