With stock prices still high and enabling mergers of unprecedented size, bank executives have a way of explaining the strategic benefits of getting bigger. They say they will stave off competition, gain scale and technology economies, and solidify a national or superregional business.
None of this is possible without a large number of customers. The conventional wisdom is that it is cheaper to buy customers than to expand one's own customer base. In a form of "irrational exuberance," huge premiums are being paid to acquire banking customers.