HSBC is making headway in Australia's credit card market and can thank direct mail for the aggressive rate of customer acquisition.The bank increased its market share by 50 per cent, from a share of 1.2 per cent to 1.8 per for the year to July 2007, according to the Australian Payment Cards Report, prepared by Michael Ebstein at MWE Consulting.The market share gains have been driven by persistent campaigns based around zero or low interest rates on balance transfers, direct mail marketing and retail point of sale business funding for Bing Lee and JB HiFi.Rod Hyde, head of consumer finance at HSBC Bank Australia, said the direct marketing campaign had been very successful, with strong demographic research identifying customers likely to take up the offer."It (direct mail marketing) is cold calling to an extent, but really we have a pretty good idea of the propensity of that customer to accept the offer."We believe we have the most marketing efficient dollars in the industry, and we measure marketing spend versus receivables growth."The customer identification strategy models were built in house, and were based on successful international campaigns by the bank."Due to having better models to identify potential customers, our bad debt rate is going down and I definitely expect our market share to continue growing, probably at an even higher rate over the next two or three years."We are constantly signing up new retailers, so we are constantly having record months."The HSBC credit card book is around $750 million, with the lowest purchase rate currently 11.95 per cent.