Banking giant Wells Fargo (NYSE:WFC) just posted another quarter of double-digit revenue and earnings growth, a feat it has achieved consistently for two decades now.

Second-quarter details echoed a recent investor presentation where Wells touted its customer-focused culture as a key factor in its increasing revenue. The company has earned its success by keeping customers happy  while planning more internal investments and acquisitions.

This battle-tested strategy led to quarterly sales growth of 13% and diluted earnings per share that improved by 10%. The company also completed an  acquisition of CIT Group's (NYSE:CIT) domestic construction lending business -- a very good fit for it -- and is set to purchase Greater Bay Bancorp (NASDAQ:GBBK) by the end of the year to further bolster organic growth.

Some of Wells' key banking metrics continue to lead the industry. Its quarterly net interest margin came in at 4.89%, while returns on assets and equity grew to 1.82% and 19.6%, respectively. Non-interest income, average loans, and average deposits also grew in the double digits, which management attributed to more business from its current clients.

Management doesn't seem to be too worried about the subprime mess, saying that "delinquency rates in both our prime and nonprime portfolios remained significantly better than published industry rates." Finally, total nonperforming assets increased slightly year over year to 0.79% of loans, but fell slightly below the 0.82% posted in the first quarter of this year.

Add it all up and it was business as usual at Wells Fargo. With control of only about 3.5% of the total financial services industry profit, it likely will only continue to catch up to rivals Citigroup (NYSE:C), Bank of America (NYSE:BAC), and JPMorgan Chase (NYSE:JPM), who have consolidated their way to leadership positions as money-center banking giants.                                  

For related Foolishness:

Bank of America and JPMorgan Chase are Motley Fool Income Investor recommendations. Want to get paid to invest? Advisor James Early can show you how with an all-access 30-day free trial to the newsletter service.

Fool contributor Ryan Fuhrmann is long shares of Wells Fargo, but has no financial interest in any other company mentioned. Feel free to email him with feedback or to discuss any companies mentioned further. The Fool has an ironclad disclosure policy.