AdDuplex released its monthly report today, showing Windows usage based on usage of apps that run the AdDuplex SDK v2 or higher on the day of March 26. AdDuplex runs on over 5,000 Microsoft Store apps.
Since last month, the Windows 10 October 2018 Update has only seen a modest increase, from 21.2% of Windows 10 PCs to 26.4%. That mostly comes out of the April 2018 Update's usage share, which is down from 71.6% to 66.3%.
Some earlier versions saw modest declines as well, with the Fall Creators Update falling from 3.7% to 3.5%. The Creators Update and earlier, which is now grouped into one instead of being broken up by version, went up from 3.2% to 3.4%. Also, the number of Insiders spiked from 0.2% to 0.4%, which is typical when we're close to a new version being launched.
We can see that Windows 10 version 1809 has had the slowest rollout of any version of the OS. Initially released on October 2, it was eventually pulled on October 6 due to a variety of issues. It wasn't until November 13 that it was re-released, and the update really hasn't gained much traction still.
Now, Windows Insiders are testing the potential RTM build for Windows 10 version 1903, so it seems that many users might end up going straight from version 1803 to version 1903.