DALLAS – Thirty-four credit unions which process with TNB Card Services, the card processing arm for credit union owned Town North Bank, have seen strong success using a balance transfer program designed by the card processor, TNB announced. The balance transfer promotion ran from September through November 2004. The promotion moved $5 million into the credit union's card portfolios using a direct mail letter customized to each credit union with a detachable check at the bottom. The response rate for the mailing was 2.25%, according to TNB, with the credit unions participating offering rates of between 0% and 7.9% on balances transferred before the end of February 2005. Industry observers of these programs have pointed out that balances transferred in this way sometimes do not remain long on the books and that very low interest rate offers can also hurt overall portfolio profitability, particularly in a rising interest rate environment