A survey by suggests that credit cards with travel rewards encourage loyalty among card members for purchases other than airfare.
About 6% of the estimated 95 million U.S. households own a credit card that provides air travel rewards with card usage, according to the Brittain Associates Inc. study.
"Frequent fliers with airline cards have more opportunities to charge purchases for items like rental cars and hotel rooms than other consumers," said Bruce Brittain, president of the Atlanta-based research firm.
In the phone poll of 4,040 households between Sept. 6 and Sept. 22, Brittain Associates also found that airline cardholders use their cards on average two and a half to three times more than holders of other cobranded cards.
Just over half said the card influences the flights they book in favor of the airline, and a majority said they use the card for airfare and other purchases, the survey found.
"The perceived value of a frequent-flier point is much higher than its actual value," said Mr. Brittain, explaining the popularity of travel reward cards.
Mr. Brittain estimates that each point is only worth about a penny and a half, whereas consumers believe they are earning $1 per mile.
In a separate mail survey of 9,500 cardholders, Payment Systems Inc., Tampa, found that about 6% of people who had recently acquired new credit cards cited airline rewards as contributing factors.
Payment Systems conducted the study between August 1995 and April 1996. Payment Systems also estimates that of 97 million U.S. households, 81% own a general purpose credit card.
By contrast, Brittain estimates that 67% of 95 million U.S. households have a general-purpose credit card.
The Brittain study revealed that American Airlines' American AAdvantage portfolio is the industry leader, with twice as many cardholders as its nearest competitor, United Airlines. He would not specify how many cardholders there were, but he attributed the lead to American's experience and size.
One of the newest entries into the travel rewards market - the Delta Sky Miles Optima program - grew 8% since March, Brittain found, to 637,000.
"That figure is in the ball park if applied to the number of accounts we have," said Cathy Cummings, a spokeswoman for American Express.
Delta's portfolio increase is based on "aggressive marketing campaigns and the strength of the American Express and Delta names," said Mr. Brittain.
Delta's and USAir's programs are close behind that of second- place United, added Mr. Brittain.
Four of the travel reward programs generate points that can be redeemed for travel on any airline.
Mr. Brittain called the survey a benchmark, saying the results will be used to gauge subsequent surveys.
In a separate study, Brittain found that First USA and MBNA Corp. own 80% of platinum cards issued to two million U.S. households. The remaining 20% carry a charge or credit card marketed as platinum from American Express, First National Bank of Omaha, or Patelco, a West Coast credit union.