Some have asked that this thread be removed.
Upon consideration and based on the general policy to allow open discussion here whenever possible, it will be left so that people can be properly informed of all the risks involved.
Personally I'm torn. Many say that the cc/mileage game is also inherently bad and designed to entrap people in debt, and to some extent that's true, you need to be very disciplined. But I also hear that gambling is inherently different and designed to be addictive, much like a drug dealer giving a free sample to get addicted clients. Being disciplined may not be good enough in this case.
At any rate, if anyone would like to write an op-ed for DDMS on the pitfalls/dangers of taking advantage of these offers, feel free to PM me. Happy to help edit it, but I don't feel like I have the expertise to write it.