Customer numbers have ticked past the 400,000 mark at ME, a bank yet to surpass double digit returns, but so far keeping its industry fund owners content.Credit card originations are one bright spot for the bank, while it's also thinking big on modern methods for mortgage origination.Net profit for ME fell to A$29.3 million over the half year to December 2016, the bank said yesterday, down from $34.5 million over the same period in 2015.ME said its "underlying net profit" was $40.4 million for half, a rise of 34 per cent.The net interest margin for the bank declined three basis points to 1.46 per cent, relative to the previous corresponding period "due to competition for new customers and higher funding costs," it said.The sale to RedZed of a legacy business lending portfolio, sliced $6 million from net profit.ME said its home loan portfolio increased nine per cent to $20.6 billion, while home loan settlements for the half were $3.2 billion, up 54 per cent.Around two thirds of new mortgage business flows are from brokers.The bank plans to push its spend on brand and marketing even further, supported by modern digital solutions.Jamie McPhee, chief executive of ME, said "we want to build out the best digital offering, without a branch network in the personal banking space."For us it's all about customer numbers," he said. ME's customer numbers are now close to double those when he joined (from Adelaide Bank) in early 2010.ME, McPhee said, was "increasing investment in the business, increasing marketing. Our brand experience gets better every year, and at the end of the day we grow our bottom line."What we need to do is to grow the enterprise value."