It's an instance of what we call embracing the red. We focus on the outliers. So for this 99.9 thing, we say, "Okay, folks are getting good performance. Great. We're happy with them. Folks who are getting okay performance, we're happy with them." But everyone who's at the 95th percentile mark or the 99th or the 99.9th, we need to look at them.
— Sam Guckenheimer · Visual Studio Online: The Inside Story from COTS to Cloud, San Francisco 2015 · at 17:36