Re: Shortlived dominance
These figures are also pretty relative. IDC examines the revenue/sales numbers only (if you can take their word). What about all those cases when OS is installed later? At least IDC's numbers do not correlate very well with those of web servers according to both netcraft and w3tech.
I wouldn't be very surprised if IDC merely takes the figures "from the customers" just like it did when calculating TCO for different OS's in Russian schools. The figures were ... a bit ludicrous.