Some investors are concerned over how long the consumer can hold up. So far, so good. American Express (NYSE:AXP) finished 2003 strongly, fueled by higher cardmember spending and a rising stock market.

Fourth-quarter revenue grew 14% to $7 billion, while earnings increased 12% to $763 million, or $0.59 per share. Excluding a charge related to a change in an accounting rule, the company earned $0.60 per share.

Net income for the flagship Travel Related Services unit -- which includes the credit card business -- jumped 10% year over year to $606 million in the quarter. Driving growth, American Express added 3.5 million cards-in-force over the year, while also benefiting from improved credit quality -- though gains from lower loss provisions and funding costs were "partially offset" by increased marketing expenses.

Even more impressively, American Express Financial Advisors -- the company's asset management business -- saw fourth-quarter income before the accounting change climb a whopping 28%. In June, the company spent $571 million to acquire Threadneedle, a U.K.-based asset manager. That acquisition -- as well as a rising stock market -- bolstered American Express' assets under management, contributing to the gains.

As Fool Matthew Emmert said in July, "The company appears to be focusing its global reach, particularly in Europe." Sure enough, the Threadneedle acquisition is already paying dividends, and we would expect further additions to the company's asset management group, should the opportunities arise.

Overall, the results were impressive. With a strong brand, an attractive credit card business, and an improving investing climate, American Express remains a Rule Maker -- the kind of company Fools want to own. And valuation? This is no screaming bargain, but it's far from overwhelmingly expensive at less than 20 times 2004 earnings.

Give us your take on the American Express discussion board -- only at Fool.com. Jeff Hwang owns shares of American Express, and can be reached at JHwang@fool.com.