National Australia Bank's decided to begin to exploit its issuing relationship with American Express as a customer acquisition tool rather than as an essentially defensive relationship for its credit card business.NAB's at the start of the week introduced a variant on the Ant-branded AmEx credit card that promises "never any annual card fees", according to promotional material. The card provides up to 44 days interest free and then an interest rate of 16.95 per cent, which is getting into the high end of interest rates. The card includes access to a rewards program, though not as generous as that offered by American Express directly for a similar card, though with an annual fee of $94.NAB claims that market research shows there's support for the "no annual fee" concept among their customers.NAB's taken the trouble this time to promote the no fee Ant card at its consumer bank website in Australia, a site that you would search in vain for an opportunity to apply for, or learn any product details about, earlier versions of its Ant card. NAB doesn't list any of the American Express cards, including the new annual fee free card, in the credit card comparison segment of its site. It's much the same at the ANZ And Westpac website in relation to the Diners Club and American Express card offers from those banks.To that extent, NAB's approach as an AmEx issuer is similar to that of Westpac and ANZ (which issues Diners Club cards rather than Amex), which is essentially defensive; a product to the call centre can promote to customers when they ring up to close down an account.NAB's initiative is of interest for a couple more reasons. One is that the gradual rise in the issuance by banks of AmEx and Diners-brand cards, which aren't subject to the same regulatory controls as Bankcard, MasterCard and Visa, has to be hastening the inclusion of the two so-called three-party schemes within the Reserve Bank's regulatory net.The second is the wonder that it's taken more than 15 months since Westpac introduced the Virgin Money-branded MasterCard, in May 2003, for any competitor to respond. Westpac attracted more than 400,000 customers to the Virgin Money brand in that time.Rohan Gamble, managing director of Virgin Money said yesterday that, "It's finally good to see someone follow our lead. They've paid Virgin Money and Westpac a kind of complement."But it's give with one hand and take it with the other as we expect with the incumbents. By international standards [the interest rate] is still amazingly high."We continue to say that fees are an antiquated feature of the Australian credit card industry. I look forward to NAB rolling out the no fee promise to their entire customer base."