When it comes to retail transaction banking, the discussion is usually dominated by commentary about the growth of internet and mobile usage. However, data on customer behaviour released by the Commonwealth Bank with its 2012/13 financial results yesterday shows that point of sale is really where it's at.The number of CBA customer transactions going through point of sale terminals has risen from 700 million, in 2003, to 1.2 billion in the year to June.The bank has 14.6 million customers, 52,000 staff and 1166 branches. Internet banking volumes have grown much faster again but are still relatively small. CBA customer value transactions (excluding balance inquiries) on the internet rose from 40 million in 2003 to 400 million in the year to June. Sixty per cent of NetBank log-ins were via a mobile device in 2012/13.The number of customers choosing to receive electronic statements rose five per cent in 2012/13.The number of CBA customer ATM transactions rose from 325 million, in 2003, to a peak of around 350 million in 2009, and since then has declined steadily, to 302 million in the year to June.The combined number of deposits and withdrawals at branches has fallen, from 130 million in the 2003 financial year to 83 million in the year to June.Other CBA customer data shows that 80 per cent of the bank's 1.8 million Australian home-loan borrowers are paying more than the required minimum monthly mortgage repayment.And the bank has identified what it believes is a clear correlation between customer satisfaction and products per customer. In June 2008, when the bank's satisfaction rating in the Roy Morgan survey was 70.1 per cent (the lowest ranking among the big banks), it had an average of 2.29 products per customer.Since then customer satisfaction has increased steadily to its current level of 83 per cent. Over the same period the number of products per customer has risen to three, with the growth in satisfaction and products per customer correlating very closely.The increase has come from sales of deposit and transaction accounts and wealth products.