I tried to open a TDW account a few months ago to get the AA bonus with the intention of tranferring my current brokerage account there.
I was quickly told I could not receive the miles because I already had an account (my IRA is with TDW). Never mind that retirement accounts are not eligible for any of their promotions, and that I had never received any bonus of any kind from them.
I promptly closed the account and left my brokerage account where it was before.