When Capital One Financial Corp. CEO Richard Fairbank said digital was the way his bank does business, he wasn’t kidding.

Almost two-thirds of our customers have signed up for online and mobile banking, a representative of the McLean, Va.-based company told Bank Innovation yesterday. With some 16 million deposit accounts and as one of the largest credit card issuers in the country, two-thirds comes out to a large number.

Other large banks are seeing mobile enrollments in the 20% range. Bank of America Corp., for example, reports 30 million active online users out of about 66 million deposit account holders — less than 50%. But Capital One does not specify that its users are “active,” the most generous definition of which usually means the user logged in within the last 90 days.

The bank is also launching innovative mobile features, such as geo-sensitive offers in concert with San Francisco-based PushPoint. Fairbank told investors lately the bank was “investing heavily” in talent and technology related to payments. A major war is developing as digital players move into the point of sale, with PayPal, Square and now Amazon, which recently acquired mobile payments startup Gopago, all in the fray. The banks have so far held back, but Capital One certainly has the chops and tech talent to compete

Capital One, known for being one of the largest users of the US Postal Service’s offerings to mail its credit card offers, also appears to be one of the most digital big banks — that’s called attacking on all fronts.

UPDATE: According to FDIC data, ING Direct — now rebranded Capital One 360 — contributed about 7 million digital accounts to Capital One’s userbase of 16 million. On the deposit side, therefore, it may be that the majority of Capital One deposit account customers came to digital before they came to Capital One. The credit card side is, of course, another matter.