Then someone realized it was also a good early warning system for new viruses, as many viruses would crash their host process in novel ways that were unlike the usual software-induced errors.
WER reports also could do other things. Sometimes bizarre, impossible crashes would happen. Microsoft would investigate some of these by showing a popup to the user inviting them to participate in analysis. If the user consented, they were put in contact with a Microsoft engineer. Turned out a lot of people were running unstable, overclocked hardware sold to them by vendors who had fraudulently misrepresented the hardware.
The telemetry that is out there is amazing, but not as amazing as the secrets it can reveal.
The original devblog from 2005 is (https://devblogs.microsoft.com/oldnewthing/20050412-47/?p=35...). Aside: Upon pulling that up, I recognized the author as the one who wrote my favorite article about undefined behavior (https://devblogs.microsoft.com/oldnewthing/20140627-00/?p=63...).
[0]: https://www.goodreads.com/book/show/18465875-countdown-to-ze...
It doesn't take a great deal of sophistication to come up with some of these things, just a bit of cleverness and exposure to the possibility of cleverness.