We live in the age of the customer, as American Banker's recent Financial Services Marketing & Innovation Symposium in New York made clear. Here are a few of the biggest takeaways from the event earlier this month.

First, the banking sector is placing increasing focus on developing products and services for the unbanked and underbanked, a category that includes 28% of U.S. households. Consumer trust in banks took a big hit in the aftermath of the financial crisis, leading some people to shift away from traditional financial services. Meanwhile, some millennials are rejecting the banking sector altogether. Now a demographic that was once targeted by select financial institutions is being pursued by global powerhouses like American Express, which offers two products-Serve, a prepaid card, and Bluebird, an online checking account-aimed at this customer segment.

American Express's experience working with unbanked and underbanked customers has shown that the average person wants financial institutions to "show me you know me, reflect who I am and respect me," according to Mary Ellen Jelenek, who heads the company's Serve and Bluebird portfolios. That's a relevant message for every customer segment.

It's also important to note that mobile banking is an essential part of reaching and servicing this population. The Federal Deposit Insurance Corp. reports that 32% of underbanked customers use mobile as their primary banking channel, as opposed to 22% of fully-banked customers.

Second, the financial industry is waking up to the fact that millennials need to be taken seriously. An enlightening presentation by Anne Hubert of Viacom's brand consulting division Scratch helped me and many others I spoke to at the conference understand this group a little better. The banking industry is ripe for disruption, according to Scratch's three-year survey of 10,000 millennials. One-third of millennials are open to switching banks in the next 90 days, while almost half are rooting for tech start-ups to totally overhaul the way banks work. Meanwhile, 53% agreed that their banks do not offer anything different from their competitors.

Hubert encouraged banks to refresh their thinking about millennials and view them not as entitled but as a group with enormous potential. Young people today have been raised to feel confident about their ability to achieve their goals, Hubert explained. Banks can connect with this group by showing millennials how their products and services can help them realize their ambitions. She told bankers to work to "understand them like our future depends on it."

Lastly, banks are working harder to differentiate themselves from one another on the basis of service. In order to better serve their customers, companies are increasingly incorporating technical and digital skills into their marketing teams. A number of speakers talked about the importance of combining right brain (creative and intuitive) and left brain (logical and analytical) marketing talent. However, the broad recognition of this fact has created what some referred to as a "war for talent" in the realm of digital marketing.

Banks are also moving to a "test and learn" marketing approach. Senior executives recognize that their best ideas and extensive market research could still be trumped by actual customer behavior. Putting a new idea into the market in order to better understand how consumers will react is critical to hitting the mark.

On the subject of hitting the mark, Deborah Van Valkenburgh, PNC's senior vice president of strategic brand management, talked about the importance of demonstrating digital capability and functionality to customers. PNC is using videos that tell customers how to navigate that new app they've downloaded in an effort to make using the technology habitual. The entire service proposition was nicely summarized by Van Valkenburgh's explanation of PNC's goal: "When a customer comes to us, online, on mobile or in branch, we want them to get what they came for in such a way that they want to come back."

Derek Corcoran is the chief experience officer at customer experience management firm Avoka. Follow him on Twitter at @cxofficer.