An army that takes its fight to a new front is always in danger of leaving its old post exposed.

Banks may face a similar problem in expanding their digital financial services offerings, according to a new study of online services at 16 financial institutions.

Those banks are focusing so hard on mobile-banking services that their Web-based products and services are being neglected, and that could turn off customers, according to Corporate Insight, a New York consulting and research firm for the financial industry that issued its annual Bank Monitor Awards on Tuesday.

To be sure, consumers of the largest banks have an array of bank services available to them online. And it's obvious that banks have to upgrade and improve their applications for smartphones and tablets.

The problem lies in the fact that consumer banking websites have become "stagnant," as many of the banks Corporate Insight evaluated this year are virtually unchanged compared to last year, said Alex Filiaci, a senior analyst at Corporate Insight.

It would be preferable if banks adopted an "omnichannel" approach, in which all forms of consumer contact were improved simultaneously, instead of just trying to improve mobile, he said.

"It really seems like [the] Web is less of a focus and that more improvements are being made to mobile," Filiaci said. "It would be better if banks tried to put their best foot forward in all channels."

Furthermore, websites tend to offer far more features than mobile apps, and are more useful to consumers, Filiaci said. Since many, if not most, banking consumers still use websites to conduct their financial business, banks should not neglect the format.

"Especially when it comes to things like account maintenance, statements, ordering checks and the type of things that are serviced through filling out a form, those little extras are really just web-only," he said. "They aren't fully integrated into mobile apps yet."

Steven Reider, founder of the consulting firm Bancography, agreed that many banks have neglected their websites, although he said it may not be because they have shifted to mobile banking.

"It seems that many institutions complete a website design and then check that off the list as complete forever," said Reider, who was not involved in the Corporate Insight study. "Banks should endeavor to use the website's distinct capabilities to regularly update it with new information. Just as branch merchandising must rotate periodically, else the branch look grows stale, so should website content."

Websites were not completely ignored by all the banks in Corporate Insight's survey. In one of the year's best upgrades, JPMorgan Chase improved its offering of account alerts, adding a feature that lets customers respond to the bank instantly upon receiving an alert.

BB&T, in Winston-Salem, N.C., which was surveyed by Corporate Insight for the first time this year, made widespread upgrades to its Web platform over the past 12 months, such as making it easier to find options for managing checking accounts, and including applications for opening new accounts.

And Ally Bank in Detroit added something to its site that no other bank has. On the portion of its site that is only accessible to customers via a password, Ally provides a listing of all its products and services, broken out with fees and rates for each. That kind of blatant selling of a bank's products is almost never included on a bank's password-protected site, and is typically reserved for the portion of a bank's site that's available to the general public, Filiaci said.

Ally's product breakdown could either be seen as a benefit to consumers, or an annoyance, Filiaci said. On the one hand, it could help a consumer to comparison-shop. But it could also irritate customers who already have everything they want from Ally and don't need to be subjected to the sales pitch, he said. Ally's product listing is presented modestly and is not intrusive to the user, Filiaci said. But, he admits, that type of cross-selling "is usually more subtle" when conducted on a password-protected site.

The company responded that it added its "Explore Products & Rates" section after customers asked for a way to view the bank's current products and features without signing out of their account, said Andrea Puchalsky, a bank spokeswoman. Customers can also get a new product without having to re-authenticate their account, she said.

As for the overall survey results, Citigroup took home the most accolades from Corporate Insight, based on eight different categories, such as the ability to search for specific transactions in a user's account history, and the level of control customers have in scheduling money transfers.

Corporate Insight limits its survey to the 16 banks in its coverage universe. It is certainly the case that plenty more banks and credit unions offer well-designed online banking products to their customers, but they are not included in Corporate Insight's yearly survey, Filiaci said.