As the time to pay the AF on my Delta Gold card was approaching, I did a check of pre-approved offers while logged into Amex, to see if there were any upgrade offers for it (those upgrade offers had disappeared from my account Feb 1 when the new Delta card benefits came out). One of my "pre-approvals" was for a Delta Blue card with a decent signup offer (15k for $1k spend). I go to apply to see what will happen, and it says I'm ineligible because I have a Delta Gold card open.

Say what? Why in the world is Amex giving me pre-approved offers for cards that their own system says I'm not eligible for???

I understand that pre-approved doesn't really mean pre-approved from a credit approval standpoint, but why would Amex take a card which is conflict with a card I already have and put it on my pre-approved offers list?