Forming partnerships that offer scale and distribution for American Express Co.’s Serve online and mobile payments platform is how the new service plans to navigate the complex ecosystem of digital payments and gain users.

“There are certain verticals we are very interested in,” David Messenger, executive vice president of Amex’s online and mobile unit, tells Bank Innovation.

One “key” vertical catching its attention? Telecom carriers. In fact, Serve, which enables P2P payments over mobile phones, online checkouts and at certain merchants, announced last week that it scored a major alliance by inking a deal with Verizon Wireless, the largest US cellphone company. Serve’s platform will be integrated onto many Verizon mobile phones and tablet computers in upcoming months. In turn, Verizon customers can make payments and redeem offers for goods and services directly from their mobile devices through Serve.

Because of the alliance, Messenger says Serve will gain distribution as the payment option will almost be “somewhat of a default” on the devices. The value of Amex’s alliance with Verizon — which is committed to the Isis mobile payments platform — centers on helping the carrier engage in mobile payments today, with an almost “seamless one-click” checkout, he says. Though many terms for the Verizon deal aren’t disclosed, Messenger says Serve is providing the carrier an expanded revenue stream through mobile payments, carrier billing, and enabling Verizon’s customers to redeem offers and coupons through their mobile devices.

Recently, Serve also partnered with Sprint Nextel Corp.

“Carriers are one key vertical for us,” Messenger tells Bank Innovation.

But Serve partnership opportunities certainly are not exclusive to carriers.

“We are looking at major merchants where we can provide value into online/offline [transactions],” he says, adding that Serve is also looking to retail banks for alliance opportunities.

To drive up usage volume, Messenger says some direct Serve marketing will circulate this month. Ultimately, though, the main effort to grow out Serve’s user base will be accomplished by increasing partnerships, he says. Additionally, part of Serve’s future growth involves interacting with social networking sites.

“Decisions are getting driven from social data,” Messenger says. One challenge with social networks’ reliability, though, is that they allow consumers to present whatever versions of themselves they wish to present. In other words, profiles are not always accurate portrayals.

Looking ahead, the primary challenge for Serve gaining traction are getting consumers to use the payment system.

“People tend to be creatures of habit,” Messenger says, explaining the payment habit of pulling cards out of a wallet at POS is tightly instilled. Plus, privacy and security concerns are driving away a population from experimenting with innovative ways to pay. But because AmEx is “fundamentally” a trust security and service, Messenger says Serve can rid consumers of those concerns.

Though just officially launched in March, Serve has already gleaned some usage trends from a market pilot held earlier in Oregon. Messenger says Serve had an “immediate appeal” for millennials, household CEOs — which he defined as the people responsible for paying the babysitter, for example — and small business owners. In particular, Serve resonates with younger generations since they have grown up on mobile phones as their primary data source, points out Messenger.

“Growth of mobile phones — especially smartphones — is really a tipping point for us,” he says.

Plus, Serve — which has its own budget line at Amex — seems to have flowing resources to help make the platform a consumer hit.

“We have various resources being allocated to Serve,” Messenger says. “We have all the resources we need to keep moving at full speed.”

Messenger’s direct team, for one, is around 150 right now and expanding.

“We are very much in growth mode,” he says, especially as Serve eventually plunges into the international market. “We are really excited about what Serve will become. [It’s] a catalyst for moving the mass market into new form of payments.”