Banks have a cost problem. The costs of a typical bank are anywhere between 60% and 80% of income. Add credit losses and fines, and little income is left to return to shareholders.

That's one reason why the conventional wisdom among digital gurus is that it is only a matter of time before technology players with low-cost models will disrupt the banking industry. Cursed by their incrementalist approach to innovation and cost cutting, incumbent banks are bound to fall behind.