Platinum credit cards boomed in 1997, fueled by high volumes of mail  offers and easy qualifying criteria, a market researcher has concluded. 
Many banks introduced platinum cards during the year and promoted them  heavily. As a result, about 10.8 million bank-issued platinum cards were in   circulation as of early fall, up from only two million a year earlier,   according to Brittain Associates Inc. of Atlanta.     
  
Brittain surveyed 6,037 people between Sept. 6 and Oct. 7 in its second  annual look at the platinum bank card market. 
In 1996, Brittain identified four banks offering platinum cards and said  First USA Inc. and MBNA Corp. were by far the leading issuers. 
  
Broader MasterCard and Visa plans kicked in last year, and of 18 issuers  First USA and its new parent company, Banc One Corp., took the lead, but   Brittain did not reveal its market share. MBNA and Citicorp tied for   second, each with about a 23% market share.     
American Express' Optima platinum card came in at 6%.
Visa platinum cards outnumbered MasterCards by about four to one,  Brittain said, but MasterCard disputed Brittain's finding. It said more   than a third of platinum bank cards are MasterCards.   
  
Horse-race issues aside, the Brittain survey underscored the popularity  of the card industry's latest marketing wrinkle. 
"We see a good indication that platinum cards are being used," said  Bruce Brittain, principal of the consulting firm that bears his name. 
Moreover, he said, the portfolios are highly profitable, withcustomers  who carry balances from month to month. 
"Almost half the people we talked to who had a platinum card said they  had not paid it off in full the last time around," Mr. Brittain said. In   newer portfolios "it's unusual to see nearly 50% of the customers saying   they are revolving their balances."     
  
The banks' rush to platinum accelerated over the last year, and now  barely a week goes by without a new product being brought to market. 
In a sign that the platinum card market may be maturing, issuers are  targeting smaller customer groups, but not necessarily upscale ones. In the   last month, First USA introduced a Loehmann's Insider Club Platinum Visa   for people who shop at the cut-price retail store and a cobranded Visa   platinum card for customers of New York Life Insurance Co.       
BAIGlobal Inc., which tracks credit card solicitations, said platinum  cards were largely responsible for the record-high mail volumes seen in   1997.   
The mailings peaked at 881 million pieces in the second quarter; 41%  were platinum card offers. 
Platinum offers made up 21% of mailings in the first quarter of 1997 and  5% in the second quarter of 1996. Statistics have not yet been compiled for   the third quarter of 1997.   
"The platinum card is filling the position historically held by gold  cards, which in recent years have deteriorated to a commodity product,"   said Lisa Itzkowitz, director of marketing for BAIGlobal in Tarrytown, N.Y.   
Among the issuers that introduced platinum cards in 1997 were units of  Chase Manhattan Corp., Capital One Financial Corp., NationsBank Corp., and   Citicorp.   
The bank platinum products are of a different genre from the American  Express original, a silver-hued charge card that costs $300 a year and   comes with a lengthy checklist of perks and privileges. Instead of the   travel services and other benefits that American Express offers with the   flagship platinum card, bank versions come with more modest enhancements   like lost luggage insurance.         
The Brittain survey included people who hold the American Express Optima  platinum card-a revolving credit product-but not American Express' platinum   charge card. Mr. Brittain said he excluded the latter because it is "a   completely different product."     
He put the number of American Express platinum charge cards at 600,000,  but an American Express spokeswoman said the number was more like 400,000,   or just under 1% of the company's cardmember total.   
Bank-issued platinum cards "don't really compete with our platinum  charge card, because the level of services is drastically different," said   Gail Wasserman of American Express.   
American Express began marketing the platinum charge card to the highest  end of the affluent consumer market in 1984, the same year it trademarked   the platinum name. For years, no other company attempted to issue platinum.   
In September 1996, after a handful of banks had started using the name  on new products, American Express sued First USA's credit card bank for   patent infringement.   
In an August 1997 settlement, American Express retained its platinum  card rights worldwide. Visa International's member banks retained the right   to offer platinum cards as long as the bank or association names were   clearly printed on the cards.     
As bank issuing took hold, industry observers said, the platinum cards  came to resemble their gold relatives. The services, interest rates, and   credit lines associated with platinum and gold cards have converged.   
"The only difference here is that platinum cards are holding out the  promise of much larger credit lines, at least in promotional material," Mr.   Brittain said. "But $100,000 is just the promise, the potential-most of the   time the actual credit line offered is much lower."     
As platinum gets into more and more hands, it can lose cachet. "When you  drop the minimum household income level to $25,000 or $30,000, as some   issuers have, you're not talking about a really exclusive chunk of the   population," Mr. Brittain said.     
"There was a replacement strategy on the part of the banks," said Ms.  Wasserman of American Express. "That's not national growth, its   conversion."   
Some banks, she added, sent free platinum cards as upgrades to gold card  customers. She said she would like to know how many of the nearly 11   million platinum bank card holders estimated by the Brittain survey "were   converted gold cards."     
Mr. Brittain said he did not track that information. "When we found a  platinum household, we asked, 'Do you have platinum Visa or MasterCard?'"   he said. "Some had both."   
MasterCard considers itself "a significant player in the platinum  market," said Myra Koutzen, vice president of premium card products. "We're   really working closely with the members to leverage this new program."   
She said about 34% of last year's mailings for platinum cards  specifically offered the MasterCard brand, and an additional 12% let   consumers decide between MasterCard and Visa.   
"We know that response and approval rates are about equal between  MasterCard and Visa," Ms. Koutzen said. 
Mr. Brittain said MasterCard could claim higher platinum numbers than in  his survey because the association "doesn't take into account attrition   that has not yet been reported."   
Mr. Brittain said Citibank's platinum program growth in 1997 was  remarkable. Citibank "jumped into it with both feet" since introducing its   program in April. "Six months later, they just charged up to a tie for   second place in market share."     
A Citibank spokeswoman said no bank executives were available to discuss  their platinum strategy or its results.