I think you can still use something of a hack to shop at Costco and rack up AmEx rewards. You can purchase gift cards online with pretty much any credit card a

I think you can still use something of a hack to shop at Costco and rack up AmEx rewards. You can purchase gift cards online with pretty much any credit card and then use the gift cards in the warehouse. A co-worker did that with his rewards Visa for a long time when AmEx was the only credit card accepted in Costco warehouses.