Given the challenges of new credit in the current marketplace, credit card issuers are focusing more on existing customers. Direct mailings now offer all sorts of bells and whistles . . . . perks and rewards to current cardholders. A new report found that the number of credit card direct mailings sent to non-customers dropped 11% while credit card offers sent only to current customers increased 16% last year. Mintel Comperemedia says that in 2005, 56% of credit card offers sent to current cardholders advertised balance transfers or convenience checks. By 2007, however, these types of offers lost out to direct mail pieces promoting non-card products, such as bonus points or rewards. In 2007, 57% of direct mail sent to current customers advertised such non-card products..