Credit card companies better sweeten their offers. According to BAIGlobal in Tarrytown, New York, response rates to credit card come-ons sank to an all-time low of 1 percent last year. The industry is evolving into a commodity market, the research firm reports, with every company promising the same low interest rate, the same no annual fee. As a result, few offers stand out with consumers, who generally are satisfied with the plastic already in their wallets. Mail volume is down in the industry as well. Last year, U.S. households received 2.9 billion pieces of direct mail from credit card issuers, down from 3.5 billion in 1998. So far, no complaints from consumers.