I thought I remembered reading on this board that if you got an AMEX pre-approval application that it's basically a done deal. You'd be approved. Is this true? Wife just got one in the mail today, so I'd be pretty excited to start building a relationship with them.
I'm no expert but I have also seen this and from personal experience both of my preapproved Amex's (Blue and the Platinum card) went through without a hitch. At that time I was already an amex customer with a gold charge card so it may be that there are some differences between preapproved offers for new and existing customers. Others of course may have had different experiences.
