I know our readers are not fans of the fuzzy maths we often use to attempt to find out how many Windows Phone 7 handsets are out there, but if we accept Gartnerâ€™s figure of 1.6 million sold to end users in Q1 2011 it does add an important data point which allows us to calibrate the other main source we have been using â€“ Facebook activity data.
Using this handy collection of data we can see at the start of Q1 2011 there were 222,194 monthly Facebook users of the WP7 Facebook app, and at the start of Q2 2011 463,898. This represents the addition of 241,704 users over the 3 month period. Accepting Gartnerâ€™s 1.6 million number, we get a ratio of 6.62 real users for each Facebook user.
If this ratio held, this means the current 564,334 users represents 3.73 million Windows Phone 7 handsets in the wild.
Running the same calculation for the integrated Facebook app produces a similar number of 3.83 million Facebook users.
Using the same ratio we can see in Q4 2010 1.47 million WP7 handsets were sold, in Q1 2011 1.6 million (from Gartner) and so far in Q2 2011 665,000 and projected for the full quarter 1.2 million, representing a decline in the number of new users, rather than the expected growth.
Of course all of this depends in the accuracy of Gartnerâ€™s numbers and the ratios remaining the same, but simply looking at the rate of FB users growth from the graph above it is clear the rate of growth has reduced.
Of course none of this tells us why, but at the most basic level if could simply be the lack of new handsets to stimulate demand. With a new Android handset announced every week selling the same old Windows Phone 7 handset for the last 6 months will certainly be difficult.
How do our readers feel about the numbers? Let us know below.