From Credit.com via Yahoo Finance:
Rewards credit card users are getting used to the idea of earning valuable points, miles, and cash back for their spending. At the same time, the card issuers are becoming ever more dependent on offering these rewards in order to attract and retain new cardholders. Read more
But in their frenzy to acquire valuable new customers, do banks sometimes get a bit carried away when it comes to the rewards they offer? Let’s take a look at what happened with three cash-back credit cards that appear to have offered more rewards than could be sustained.
If the credit card offer looks too good to be true, the terms will probably be modified at some point (as in the three examples cited) - but it can be very profitable while it lasts.