Surely if you want to track users over a much longer (obviously this works very well for even a large number of sessions) period of time you wouldn't rely on pl

Surely if you want to track users over a much longer (obviously this works very well for even a large number of sessions) period of time you wouldn't rely on plugin and web-font data staying the same. I suppose you might have a confidence equation based on overlap, since changes would likely be small and gradual.