"There"s no doubt that part of the "Oh, hell" moment we had a couple of years ago was that we needed to focus on retention and servicing customers, hence, the whole push over the last couple of years in the "Which New Bank?" story," Harley said.

Warning about the risks of losing lower revenue customers, Harley said it was easy to shed customers but far harder to reduce proportional cost overheads because of high-fixed costs. The situation has resulted a re-evaluation in customer data, and the way it is used.

"One of the most successful data strategies has been managing customer attrition. That"s why we have had a comeback on home loans. We are now at the point where we can put the credit [risk] people and analytical [marketing] people in the same room."

The result of integration so far has been an integrated fraud risk score based on the profile of credit applications.