My husband has 3 open AMEX Business Platinum cards. He's received some targeted offers that I've ignored. This week, he's received another targeted offer. Is there any risk in opening a 4th card? Every one will be canceled at the one year mark. The value is the signup bonus. It makes no sense to me that AMEX keeps making these offers. But they do. Is there any risk in accepting the recent offer? He has a substantial cache of Membership Reward points now. I don't want to put them at risk.