Why do browser cookies expire?
So, if I log into Gmail, Twitter, eBay, or my own blog on a computer, and opt to have my user information saved, then obviously I’ll want to log in using that information whenever I use those sites, for as long as I use the site and the computer is my computer.
If it stops being my computer at any point, even if I don’t reformat the hard disk, I’ll obviously delete all browser personal information.
So why on earth do Twitter and Gmail set their cookies to expire after a fortnight, and eBay in 24 hours? What possible use could there be in not just setting them to last forever?
It’s not a huge thing, obviously, as my browser still stores the passwords – but even causing me very, very mild annoyance seems bizarre when there is no benefit at all to me or the supplier from the mild annoyance caused…