There are also a number of other features being implemented into the game such as exclusive card backs, friend challenges, activated abilities and the drafting system. (mmogames.com)
The basic annual income requirement can go up to hundreds of thousands for the most exclusive cards. (gobear.com)
In addition to earning miles on every purchase, travel cards also have exclusive card membership rewards, like lounge access, no foreign transaction fees, and free checked bags. (cardrates.com)