> until you're confident that no browser could reasonably be still loading version X of the page During experiments of this stuff at a big company (which saw a

> until you're confident that no browser could reasonably be still loading version X of the page During experiments of this stuff at a big company (which saw a large portion of the web during this time): - we saw most (>80%) of users staying on a web app ~2-3 days (most likely skewed from people leaving tabs open over the weekend). - 95% was ~2 weeks - 100% was about 600 day (yes, apparently we had users with a tab open for nearly 2 years) If you are seeking 100%, you are going to be waiting a while. : this is 100% from memory, I don't work there anymore.