This would be helpful when...
I remember the days when we used the standard Drupal "sticky at top of lists" which became problematic when people couldn't tell what had already been deemed "sticky" and suddenly the order of posts made no sense whatsoever, since almost everything was sticky.
Maybe the ability to "pin" a post? And only one? With some visual cue (like a push pin icon, sticky honey or bubble gum icon, etc?) :)
I had a recent use case where UCD Advance wanted to ensure a certain pod stayed at the top of the pod channel. I tried setting the post date to something ridiculously in the future (2033) and it still didn't stay at the top.