Mobile banking isn't the future of banking; it's the present. And few banks have cracked the nut on mobile banking as well as Bank of America (BAC 3.34%) has.

On the bank's second-quarter conference call, which teased out Bank of America's impressive performance in the three months ended June 30, Chairman and CEO Brian Moynihan shared a number of fascinating metrics about its success on the mobile banking front.

1. Total mobile customers

Given that Bank of America is the nation's second-biggest bank by assets, it should be no surprise that it has a lot of mobile banking customers. But given how new the technology is in the whole scheme of things, the North Carolina-based bank's progress is still impressive.

The bank had a total of 34 million active digital banking users at the end of the quarter. More than half of them, or 22.9 million, used its mobile banking app. Only JPMorgan Chase exceeds that, with 28.4 million active mobile customers. Wells Fargo, meanwhile, ranks third, with 20.4 million mobile active users.

Bank

Active Mobile Users (Millions)

JPMorgan Chase

28.4

Bank of America

22.9

Wells Fargo

20.4

Data source: Second-quarter earnings releases.

2. Mobile deposits

Mobile banking is about more than just checking your account balance. You can also set up appointments to visit a branch, locate a financial center, and process a payment.

Of all the things one can do on a mobile banking app, however, the most convenient functionality is the ability to deposit checks remotely. And you don't have to take my word for it. More than one in five deposit transactions at Bank of America are made on its app.

A pie chart showing the 21% of deposits at Bank of America are made on its mobile app.

Data source: Bank of America. Chart by author.

3. Cost of mobile deposits

Remote deposit capture isn't only great for customers, who can now deposit checks from the comfort of their own homes, but it's also great for banks. That's because it costs significantly less for banks to process mobile deposits relative to teller-assisted deposits.

How much less? According to Bank of America, it costs one-tenth of what it cost to do it over the counter. Now consider again that 21% of Bank of America's deposits are made this way, and you can see why it has had so much success cutting expenses over the past few years.

4. Digital sales

It's not just on the cost side where mobile banking offers so much potential, it's also on the revenue side. As Moynihan noted on the bank's latest conference call with analysts, digital sales now represent 22% of account and loan sales.

Brian Moynihan

Brian Moynihan, chairman and CEO of Bank of America. Image source: Bank of America.

To be clear, this seems to include sales made on both personal computers and mobile devices. But either way, it's fair to assume that the latter make up a meaningful portion of the 22%.

5. Total interactions

Finally, when you factor in all types of interactions on Bank of America's mobile app, it's clear that the technology is popular. There were a total of 1 billion customer interactions on the app in the second quarter. If you divide that out, it means that the average customer at Bank of America logs into his or her account 15 times a month, or approximately every other day.

Mobile banking is clearly a big win for Bank of America. It accordingly makes sense that its CEO would relish the opportunity to talk about the bank's progress on this front when he gets the opportunity to do so, as he did on the bank's latest conference call.