The Blue Sky from American Express is their flexible travel rewards card, meant to be a catch all of those who want an American Express Card but don't have the credit (or fly on certain airlines enough) for the Delta SkyMiles card to be attractive. The Blue Sky card provides similar enticements as many of the Travel Credit Cards, including 7,500 Bonus Points when spending $1,000 in the first 3 months, and you can use these points for statement credit towards all travel that you book on the card. This is a bit limiting as you can only redeem as statement credit - you need to make the purchase and then American Express will reimburse you - however, we generally find that the rewards system is very competitive.
In addition to the travel rewards, the card also provides an attractive savings program with Hertz and Mariott, as well as credits for cruises. You'll also have travel accident insurance, car rental insurance policies, and have the flexibility to spend your points whenever you want as they don't expire. Additionally, 7,500 points equals a $100 credit - this means that each point is worth more than 1:1, in reality each point is worth 1.33.
Ultimately this is a solid Travel Card coupled with American Express's best in class customer service. The 6,500 points to $50 is good value, but unfortunately it comes with the side effect of being inflexible - you can only redeem your points in 6,500 point intervals. That being said, this credit card is our favorite American Express overall travel card.