Is it possible to track and view/analyze traffic to a GitHub repository (possibly with referrers information) for a period longer than 14 days? That seems to be the longest period that I can see via GitHub "Traffic" graph.
From another answer, suggesting to use badges and some third party service, I navigated to a blogpost, claiming that Github now caches images from READMEs, and thus this solution won't work either, reportedly.
Best Answer
Not possible as of 2015-05-19
I wrote this message https://github.com/isaacs/github/issues/399 to https://github.com/contact and Ivan Žužak replied by email:
confirming it is not currently possible.
A better approch might be to enable Google analytics on GitHub as proposed at: https://github.com/isaacs/github/issues/446