Expiring shortened URLs shouldn't be used to implement "business logic" or security. The first person might just share the unshortened link with others; you mig

Expiring shortened URLs shouldn't be used to implement "business logic" or security. The first person might just share the unshortened link with others; you might even inspire a cottage industry of "expiring URL expander and archiver" utility, in much the same way BugMeNot exists because of stupid "free signups".