A growing number of credit card users are carrying only one card, putting pressure on card issuers to look at ways to increase loyalty and minimise attrition.According to a JD Power report on the Australian credit card market, the proportion of cardholders who have only one card has increased from 56 per cent last year to 61 per cent.The report says that card issuers are under greater pressure to demonstrate the value their product offers at a time when pricing regulation has constrained their ability to fund high-value reward programs.Twenty-one per cent of cardholders said benefits and services were the reason they chose their primary card.The report says: "In the age of hyper-personalisation, it is more critical than ever that issuers tailor their benefits and service offerings based on cardholder needs."Among its other findings, the report says people are still receiving unsolicited credit limit increases, despite the practice being outlawed last year. Fifty-seven per cent of cardholders who were offered a credit limit increase said the offer was unsolicited.It also found that use of mobile apps has levelled off. Forty-four per cent of cardholders used their credit card app in the past 12 months, which is only 1 per cent higher than in the 2018 survey.The report says: "The top reason cited by cardholders for not using credit card mobile apps is the adequacy of other channels in meeting their needs. This should be a concern for card issuers that place a strong emphasis on a digital experience and have invested in a mobile-first approach."Bendigo Bank had the highest customer satisfaction, followed by American Express and Commonwealth Bank.JD Power found that consumers like to get their credit cards from banks. Only 11 per cent said they would consider applying for a credit card from a non-bank or "non-traditional issuer".