Big banks including Citigroup, Suntrust and Bank of America are trying to learn from Amazon's use of predictive analytics to target customers more accurately. Like Amazon, banks collect vast amounts of information about their clients' spending and savings. That kind of information could be used to anticipate whether a customer needs a credit card, car loan or mortgage. This individualized approach runs counter to the traditional big bank model that relies on a high volume of transactions rather than marketing tailored to individual customers. Predictive analytic services could be more akin to the personalization associated with smaller institutions -- if it can be done without coming off as creepy or intrusive.