In the world of credit card payment key fobs, there is now one less competitor. American Express has stopped offering Express Pay, its version of a keyring-sized device that uses radio frequency identifier technology to complete payments at the cash register. The company claims there was not much consumer interest in its offering, which was only rolled out to customers in select markets like Phoenix, New York and over the corporate web site.

The technology is all the rage in the finance industry, with Visa, Mastercard and even the Royal Bank of Canada also offering their versions - payWave, PayPass and Speedpass, respectively. Canada was actually the first, with keyring devices for its credit card holders debuting in 2001, and for debit card holders in 2007.

It’s probably all for the better that AmEx is pulling out anyway. It has yet to be determined how easy it can be for a high-tech identity thief to hijack the information being sent over the low-frequency radio waves. Proponents say the cards can only work when 4 to 6 inches from a reader at a cash register, and that each card has a security cryptogram that changes after each transaction.

However, Marquette University has pointed out that, while the cards cannot easily be cloned, nothing seems to be stopping them from being read by handheld RFID readers. These can be picked up in all shapes and sizes on the Internet for anywhere from several hundred to several thousand dollars. So it may not be the best thing for identity theft protection, but it sure is convenient!