if you don't use them or don't use them enough. In the article, Chase mentions of reviewing inactive accounts, closing them, then sending you a letter in the mail. I have three credit cards and one of them is a chase card that I haven't used in over a year. I'll have to watch out for this one. Your FICO score will take a big hit if your account is closed.
http://articles.moneycentral.msn.com/Ban...hem.aspx?page=1
http://articles.moneycentral.msn.com/Ban...hem.aspx?page=1