Windows 8 sales are good, if not great, at 40 million copies in the first month

Tami Reller, corporate vice president (and chief financial officer and chief marketing officer) for Windows and Windows Live, announced today that Microsoft has sold 40 million Windows 8 licenses after its first month of retail availability.

Is that number good, bad, or merely mediocre? Probably good, but perhaps not great. Microsoft sold 60 million copies of Windows 7 in the first ten weeks of that operating system's availability, with the Wall Street Journal estimating that 40 million copies were sold in the first month.

With Windows 8 selling 40 million copies in five weeks, it seems to be selling at about the same pace as Windows 7. Considering the different market dynamics—Windows 7 was an iterative release that fulfilled substantial pent-up demand as businesses chose to ignore Windows Vista whereas Windows 8 is a more controversial update being brought to a market that is generally happy with Windows 7 anyway—this is a healthy performance. Windows 7 sold very well and matching it is no mean feat. The apparent failure to surpass Windows 7's launch could explain the mixed reports on early sales. Strong sales can still be disappointing if they were expected to be stronger still.