Visa (NYSE:V) reported solid earnings yesterday that squeezed past most estimates. Net income came in at $0.97 per share, up from $0.51 per share in the same period last year thanks in part to a healthy dose of cost cutting. The results were also juiced by a one-time gain related to asset sales. On an adjusted basis, net income was $0.67 per share.

Good news? Sure. But let's face reality: As credit-issuing banks like Bank of America (NYSE:BAC) and JPMorgan Chase (NYSE:JPM) grapple with surging defaults, and the credit card industry as a whole faces a global consumer in retreat, Visa and rival MasterCard (NYSE:MA) are looking at a serious challenge to their once-blossoming payment processing business.

For example, look at what's happened to worldwide payment volume -- a key figure in determining revenues -- over the past year:

Period Ending

Worldwide Payment Volume Growth

March 31, 2009*

(5.5%)

December 31, 2008

(0.9%)

September 30, 2008

12.4%

June 30, 2008

15.2%

March 31, 2008

19.1%

*Payment volume has a one-quarter lag. March 31 is the most up-to-date figure Visa provides.

That's ugly. When broken out, the debit side of transactions is still growing -- up 4% in the quarter -- but it isn't enough to stem the 10% decline in credit payment volume. Any way you spin it, the growth Visa enjoyed in years past -- and the growth many investors assume will continue in the future -- just isn't there anymore.

Visa's still a fantastic company. I can't say that enough. But I still struggle to see the catalyst that will get growth, ultimately reliant on consumer spending, back on track. The years ahead will not mimic years past: When the savings rate goes from flat to almost 7% in two years, consumers are screaming from the rooftops that they've left the overconsumption days behind. If payment volumes continue to decline, or even stabilize and stay flat, I find it difficult to rationally justify Visa trading for 24 times its 2009 earnings.

For related Foolishness:

Start investing today -- just $7 per trade with Scottrade. Or find the broker that's right for you.