The appeal of contactless payments may be further displacing cash, if the leap in total spending on credit and charge cards reported by the Reserve Bank of Australia for May 2017 is any guide.The credit and charge card total for April "increased by a considerable A$5.6 billion from April 2017 to $29.2 billion in May 2017," Michael Ebstein from MWE Consulting wrote in an appraisal of the data. "The May 2017 credit and charge card spend was a very solid nine per cent higher than May 2016, whilst the 23.9 per cent lift in month-on-month spend was more than double the average lift over the three prior years," Ebstein said.The month-on-month increase in value of purchases on debit - also nine per cent - "was considerably above the norm," he said.The growth in spending on debit cards of one shade or another over the last four years "has principally occurred through scheme debit, with Eftpos estimated to have maintained turnover but lost share," Ebstein said.Even so, the eftpos scheme is scrambling to catch up.More than a million eftpos Tap & Pay cards have been issued by Australian financial institutions, eftpos managing director, Bruce Mansfield, said in a media release at the weekend.That number "would reach well over three million cards by the end of the year, and 12 million by the end of next year."More than 20 million multi-network debit cards are also enabled with the eftpos Tap & Pay technology.