The banks, on the other hand, argue that the purpose of their multi-brand strategy is to ensure that one brand does not cannibalise the others. National Australia Bank ( ASX: NAB ) and Commonwealth Bank ( ASX: CBA ) also operate following the same strategy, with NAB owning UBank and CBA owning Bankwest. According to The Sydney Morning Herald, Bank of Melbourne is expanding its deposit base by around $1 billion every six months whilst Scott Tanner, the group's chief executive, has stated that the brand is making a healthy profit. However, for Westpac shareholders, one does have to wonder the impact the brand will have on overall profitability. It has been estimated that $500 million is being spent on the initiative over a five-year period, which could counteract profits made by the group, although Tanner has stated that the bank is making a "fantastic" return on each of the branches being opened.