By default, do links expire?

[twomiracles]

I had assumed not, but when I accidentally clicked on the upgrade/downgrade icon, I see that it has a drop down that is defaulting to 30 days, but the expire field shows n/a. So, does that mean it will not expire? Just a little confused .

Thanks!

[Bruceper]

Only premium and sponsored links expire. But they expire into a basic link which does not expire by default.

[twomiracles]

Thanks for the clarification!