As a customer of Bank of America (BAC 1.55%), I'm a big fan of its mobile-banking app. I use it most frequently to check my account balances. But my favorite feature is the ability to deposit checks remotely from the comfort of my home.

I'm not the only bank customer who feels this way. A recent survey by fiserv, a company that provides technology services to banks, found that 14% of survey respondents identified mobile banking through a smartphone, tablet, or other mobile device as their most preferred channel for standard daily transactions.

This may not seem like a huge percentage, but the number of mobile-banking users is growing rapidly. You can see this by looking at the trend in users of Bank of America's mobile-banking app. The latest data released by the North Carolina-based bank shows that a total of 22.9 million people are considered to be active digital-banking users of its mobile app. That's up considerably over the last few years.

Bank of America's mobile banking users.

Data source: Bank of America's second-quarter earnings presentation, slide 5. Chart by author.

While branches continue to play an important role in most banks' business models, Bank of the Internet excluded, there's no question that online and mobile banking have transformed the financial services industry.

Digital banking enables banks to reduce the number of branches they operate. Since the beginning of 2009, for instance, Bank of America has closed a net 1,603 branches, which marks a 26% decline. And while Bank of America has been especially aggressive when it comes to branch closures, all of the other major banks have followed suit.

Digital banking, and remote deposit capture, in particular, are incredibly efficient ways for banks to interface with customers. Bank of America's CEO Brian Moynihan recently said that a remote deposit costs the bank a tenth of the amount to process compared to a teller-assisted deposit.

You can get a sense for just how important all of this is to Bank of America and other banks from the fact that they frequently discuss the topic in formal settings, such as their quarterly conference calls with analysts, and from the fact that they expressly disclose how many customers use their online and mobile-banking channels.

A person checking Bank of America's mobile banking app.

Image source: Bank of America.

Bank of America's latest conference call was no exception. On it, as I discuss here, CEO Brian Moynihan delved deep into a number of important digital-banking trends, including total online and mobile users, quarterly mobile banking interactions, and the percent of sales and deposits made via Bank of America's mobile app.

Lest you have any doubt about where digital banking ranks in Bank of America's priorities right now, these trends were presented in graphs at the beginning of the bank's second-quarter presentation that accompanies its call with analysts. They were on slide five out of 28, preceding even the bank's substantive analysis of its quarterly results.

The point: Not only is Bank of America's mobile-banking app popular with consumers, it's also a favorite topic of discussion and analysis for the bank's executives.