You can establish a floor of a cardholders historical credit score.
With the introductory card you can't eliminate a high score, and with a premium card you can't eliminate a low score, but you can assume that at some point in time they had a high score with a premium card.
Not really. I have several AU's on my american express card. My sister in college for one, who certainly couldn't qualify for a similar card on her own. There are a lot of AUs.
An Amex may also indicate that at one point I had good credit. I could have a 600 now.
It's a creative product but I second the notion that it hardly seems credible. It might be able to drive incremental ROI but I'd have to see it to believe it.
With the introductory card you can't eliminate a high score, and with a premium card you can't eliminate a low score, but you can assume that at some point in time they had a high score with a premium card.