I tried once to really dig into a site’s analytics as a guide for what breakpoints I should use. Of course, that didn’t work. The numbers I determined based on analytics didn’t line up with the layouts where my content and design weren’t working well together, so I ditched that idea and just started putting breakpoints where the design and content dictated.
Ben goes on to champion the use of chunk-specific media queries, rather than layout-wide “breakpoints”:
By placing our media queries inline, immediately following the smallest styles, we can group styles by the components they impact and not worry about following a specific set of breakpoints.