They said backdating would not be a problem. When she told me the new credit limit I had to ask her again to make sure I heard right. $19,300!!! Whoever it was that said high limits beget high limits was not kidding.
When my 60 days are up and it's time for the first CLI, I'm gonna go out on a limb and assume that the standard advice of asking for 3x your current limit doesn't apply in this case, does it?
Starting Score: 690
I think Amex handles limits above $25K differently. Can't recall details but I thought I remembered posts saying that you can only go to $25K through the automated system and have to talk to a representative for anything above that. That doesn't completely answer your question, expect to the extent that if true, you wouldn't be able to ask for 3x current limit without speaking to a rep. As for whether the 3x criteria is any different when talking to a rep, I don't know.
So I got an envelope in the mail today from American Express. It didn't have the card but it did have something useful - my EX FICO. 764! Better than I thought and it would explain the awesome CL. They also include the factors that adversely affect the score:
Length of time accounts have been established (AAoA ~ 7 yrs)
Length of time revolving accounts have been established (Oct 09 & May 10)
Proportion of revolving balanced to revolving credit limits is too high (20% on Disc, 10% on MC)
Proportion of loan alances to loan amounts is too high (12k/15k & 2.3k/10k)
I suppose by gardening my cards & paying down loans it will get even higher, but as far as getting the best rates, with 764 I've gone about as fer as i can go. 
Now I'm just waiting for the darn card to arrive.
Congratulations, LTomBerry!!
I got approved for the Blue Cash Preferred as well, and have a questions for all about CL. As long as one has used the card reasonably, can one ask for a 3x increase regardles of the amount of money pushed through the card? (i.e., do I need to push the card to its limit?)
Thanks!
4.2K 
10K 
24.6K 
Well two days ago when I called they must have realized they didn't send it because it came today in a UPS overnight envelope. DW's came in a separate envelope. Mine was backdated to 2002 but hers says 2011, even though she was on the original account with me. I wonder if they'll fix that.
Next question, anyone else with the Blue Cash Preferred, does your card say "Preferred" across the left side of the card like it shows on the website? Mine looks plain, like the everyday. I wonder if they used the wrong plastic card to make mine.
Update: Just called them, they can't backdate her because she was just AU and I was the primary account holder. And they're sending replacement cards that say "Preferred" because it was printed on the wrong stock.
