American Express is accepted in certain U.S. luxury establishments exclusively such as Neiman Marcus and Costco Wholesale and widely in Europe. Walgreen's is one of the few large businesses that do not take AMEX along with a few Broadway theatres in favor of VISA and/or MasterCard.
These type of cards with the exception of Blue and the Costco TrueEarnings do not have pre-set spending limits, which doesn't look good on you credit reports since the highest balance will become your credit limit., For example, if you charge $50.00 and the billing statement closes with that amount, AMEX will reports that activity/balance but the credit bureaus will assume that is your credit limit.
Also, if you rent your residence, you have higher chances of NOT getting approved, regardless of your creditworthiness. To apply for a AMEX card, you need to have a FICO score of at least 715 with no negative information, and no more than 3-credit inquiries in the last 3-months. And you must have not been decline credit by AMEX within the last 6-months.
Another important thing you need to be aware of is if you charge your credit card with high amounts within the first 6-months, they will place your account in a "possible fraud alert" this mean that they will be asking you shortly for a financial review in which they demand from you 4-full bank statements, 2 past W-2s, 2-past 1040s, 4-pay stubs, birth certificate and a photocopy of your identification card or