They charge more in fees, and also pass on more as cashback/bonuses/prizes to customers.

For example, a visa/mastercard might be able to kick back 1~2% for cashback. American Express might be able to go 2~3%.

This is also why a lot of places don't accept Amex, the fees are higher and from the vendor's perspective they offer nothing in return.

PS - The whole credit card system is too expensive, and inefficient, but that's what happens when three or four companies run the whole game.

I use my Amex personally for both the rewards as well as extra consumer protection. Example: I recently had to re-purchase a plane ticket three times due to extenuating circumstances that the normal travel insurance would not have covered. American Express refunded both tickets from a five minute phone call. Buying the tickets with Amex saved me $1k.

They offer best perks, rewards, and customer protection (at the cost of the merchant who accepts them).

For me, who has also pushed through hundreds of thousands of business dollars, it is all about the rewards program.

It was not uncommon for me to receive several thousand dollars of Home Depot and other gift cards per year.

Based on my experience, American Express has outstanding customer service. I have also heard that they tend to be rather aggressive in their fraud protection program and they way they deal with chargebacks, often taking the side of the cardholder rather than the merchant's.

There are some really great rewards for using it, moreso than other cards.

Because its extremely handy when I'm traveling from the states to Europe.