Banks have some of the greatest stores of information on their customers, but they have yet to figure out how to use it effectively and consistently.

When it comes to deploying the technology and customer information that falls under the heading of "Big Data," banks have fallen behind retail experts like e-commerce giant It's a struggle recognized by both bankers and technology executives, several of whom have raised the issue in recent months as a top priority.

The reasons for this are varied, including privacy concerns, cost issues, and the residual impact of mergers that leave some institutions with multiple systems that don't always communicate effectively with each other. Some institutions fear appearing to invade their customers' privacy, particularly when banks have enough reputational issues already. Financial companies are also large, complex and risk-adverse conglomerates, struggling to cut expenses in the face of flagging revenue growth.

In the past few months, bank senior executives, technology specialists and the head of data specialist Acxiom discussed with American Banker what banks can and should do to better use Big Data. Here's what they had to say:

Rilla Delorier, SunTrust (STI) Consumer Channels, Sales & Service executive:

"A core layer under all those channels [branches, mobile, online] is enabling data and analytics.... How do we use that information to provide value — kind of the Amazon model — in a way that isn't invading and isn't selling?"

"A lot of it is old systems that don't talk to each other, from past mergers.... Because this is new, a lot of this feels risky" to banks generally.

Scott Howe, Chief Executive Officer of Acxiom (Nasdaq: AXCM):

"Not surprising, many financial institutions are often very big and somewhat siloed. [Using data effectively] requires institutions to work together and... a top-down mantra from the CEO."

"We're 100 yards into a marathon. Some companies have become very good at optimizing the easy stuff, the low-hanging fruit.... On the one hand, financial institutions are well-positioned to move very fast, but some of them are almost definitionally trapped into moving slow because of their own size and organizational disparity."

Manolo Sanchez, CEO of BBVA Compass:

"We all are lost when it comes to Big Data – and we have all the data.... We are best at doing certain things. So for example, a concept that's common in Internet retail, which is propensity to buy — and the algorithms that come with that — I think we are at the infancy of understanding those business models in banks. That's what Amazon and all the Internet retailers were founded on — they can tell you what you need to buy next."

Cathy Bessant, Global Technology and Operations executive at Bank of America (BAC):

"Here's the difference between what I see in banking and what I see at retailers that are great at this, using Amazon as a common example. Amazon was founded on the use of data.... It was conceived around the use of data and around the customer experience. Banks have not grown up that way. In the early days of banking, banks were order-takers, and people who came through the door became the customer base. And so we were built on order-fulfillment, not on customer experience and the use of data."

Jim Marous, consultant and publisher of Retail Banking Strategies:

"The challenge is that banks have these silos of info, so your deposit data isn't necessarily in the same place as your loan data.... The inside information is so extraordinarily valuable from a marketing and communications standpoint, and yet they don't use it."

"Overall for banks, especially the midsize and smaller banks, there are so many things on the table that the prioritization of what they should do next gets blurred."

"The bigger banks are using digital information, and it's a very big concern to make sure they don't break any privacy rules or perceived privacy rules.... But there are studies out there that say that customers want to be re-targeted [with offers]. If Amazon reached out to me to offer me a better deal, I don't care that they know about me and what I want."

Originally published by American Banker.