Shareboxed
Permanent links are convenient exactly once: the moment you send them. After that they are a liability that grows quietly. They get resent, they end up in group chats, and search engines find the ones that were never meant to be found.
A temporary link inverts that. Access is bounded in time, so the question stops being "who has this link?" and becomes "does it still work?", and the answer is no by default.
What expiry actually protects
- Forwarding. A link that has expired cannot be usefully passed on.
- Stale access. A contractor who needed a file in March does not still have it in December.
- Leaks. If a link does get out, the window in which it is worth anything is measured in days rather than years.
Counting downloads, not just days
Time is only half of it. A link that works for a week can still be used a thousand times in that week. Counting downloads puts a second bound on it: a Shareboxed share hands out the number of downloads you chose and closes when they are used up, so a share that was meant for one person cannot quietly serve a hundred.
Revoking is the third one
Expiry and a counter both run on their own. Sometimes you want it to stop now: you sent the wrong file, or the wrong person. Every live share can be revoked from the app, and the link is dead on the next request rather than at the next cleanup.
Together the three mean a shared file has a shape: it starts when you send it, and it ends whether or not you remember it.