did you get approved for amex charge or amex revolving? Sounds to me like the odds are Amex Charge, which is not a useful everyday card for someone who EVER needs to carry.
+1 Different lenders have different criteria.
Discover for instance is VERY CONSERVATIVE, as they fund themselves.
Barclay is Less Conservative the Discover, but has a whole other set of determining criteria, you want ot be careful with them because sometimes when you REQ a CLI on them , if your reports dont look good, the have a history of doing a CLD instead. It has been said that they are INQ sensitive, however I was able to successfully negotiate a CLI with more than 10 on TU, again though these INQ were more so related to my CLI requests for other cards than they were for new Accounts, which Barclay DOES NOT LIKE more than they are INQ sensitive. New accounts seem to Spook them under some circumstances.
I think you need to study the lenders, there is so much on here for them! You are in the right place.
Myfico is a place you can literally study the methodology of credit. Its amazing what you can accomplish in such a short time. Good Luck!
