The failure of Mambo as the "great white hope" for online payments has sent the big banks back to their bunkers, without any clear plans for an alternative, according to Drew Unsworth, general manager of online banking for Commonwealth Bank.Speaking at an Enterprise Ireland event, held in Sydney yesterday, Unsworth said: "I think the banks are probably sitting in their bunkers right now thinking, 'Well, Mambo has fallen over, so I think my response will be wait and see'."How long the big banks can realistically remain in their bunkers is moot. Unsworth acknowledged that the banks are facing pressure from the regulator to be more innovative regarding payments.There are also international challenges as a result of new entrants entering the payments space.  Referring to the US-based Isis payments network, which has secured US$100 million worth of investment from communications companies AT&T, T-Mobile and Verizon, Gartner analyst Robin Simpson said: "When mortal enemies collaborate on something you have to take notice. But the banks aren't collaborating on this and I think that's an opportunity missed."He added that the major payments innovations in the future could well come from outside of the financial sector, as software companies plunged into the online payments space, or Apple seized the opportunity to launch an iPhone with an embedded NFC chip,  turning it into an obvious payment device.Simpson said the Mambo collapse (BPay pulled the plug on Mambo last month after NAB, ANZ and Westpac withdrew their support) was particularly mystifying given the four big banks' successful collaboration in New Zealand on the Paymark electronic payments network and the Pago digital wallet. Surprisingly, given his position at Commonwealth Bank, Unsworth said he had never heard of Paymark. In operation since 1989, Paymark used to be known as Electronic Transaction Services Ltd. It handles three-quarters of all electronic transactions in New Zealand.Regarding Mambo's demise, Unsworth said; "I think it's very difficult to get four large organisations to agree on something that is a game-changing technology. And I think, in the end, there were a lot of cost pressures which came to bear - and you need all four to cooperate or [it will] not succeed."