My......ahem, excuse me, the employer of someone I know switched from AMEX to DC. He was allowed to keep his AMEX membership rewards points, but the company does not allow individuals to participate in the "Club rewards" program now that it's with Diners. He assumed this was for the company to get a better deal financially.
Amazingly, this company has seen a lot of their expenses move from corporate credit card to "cash" (meaning anything but the corporate card, including personal cards). The only place this will not work is with airfare, where employees must use the in house agent, and they must use the Diners.
[This message has been edited by NJDavid (edited 01-27-99).]