The Amex For Target card was the precursor to the Amex Target Prepaid REDcard (aka REDbird). It had fees to load, ATM fees, no bill pay, and no Target discount. Not a great card!
It was not heavily promoted. The occasional store that had them placed them at registers near Target gift cards. I never saw anyone use one but me and cashiers were generally unfamiliar with them. I doubt there were many active customers outside those in this hobby.
For MS it was a marginal play: among two cards allowed per person, you could load $1,000 + $3 fee up to 5 times per rolling 28-day period. Unloading by ATM at $400 a pop with $3 Amex fee, plus ATM fee, added up (one $3 Amex fee waived per calendar month). I used it for credit card minimum spends because Target is walkable for me. Credit card and debit card loading both ended at the same times as the REDcard.
Now it is departing. As of March 21, 2016, the program is discontinuing. Accounts will be closed with no replacement.
There is a $25 bonus offer to open a Serve account (URL is unique, I have 4, contact me).
My accounts all have zero balance so the notice I received does not require any action. Others I assume are instructed to spend it down or will get a refund.
This product makes sense to kill off. The much better REDcard has never been fulling rolled out, maybe it never will. With Amex flailing around these days, it is hard to see if they have a strategy or a dart board.