It's a loss that will hurt for a long time, but at least the victim is recovering. The injured party is credit card giant American Express (AXP -0.55%), which early this year failed to agree on terms with Costco Wholesale (COST -0.82%) to renew a pair of card exclusivity deals.

In the wake of the divorce, AmEx has been busy drumming up new business. For example, in March it announced it signed an agreement with brokerage Charles Schwab (SCHW -0.37%) to serve as its credit card co-branding partner.

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Better, in the retail sphere, earlier this month it announced its cards would start to be accepted at Sam's Club. This retailer, a unit of Walmart (WMT -0.18%), is kind of a Costco Junior -- it charges customers membership fees to shop in its stores, essentially warehouses stocked with bulk items.

Sam's Club isn't as big and dynamic as Costco, and the deal isn't as sweet. But AmEx investors should be happy about it nevertheless. Here's why.

Chuck, Sam, and beyond
In the wake of the split with Costco, AmEx isn't sitting around mourning for its lost love. Instead, it's acting like a scrappy young company by hustling up some new business.

The Charles Schwab deal was a definite tick in the win column. It's an appropriate customer base for AmEx, as brokerage clients by and large tend to be affluent and financially solvent.

Sam's Club, of course, is a much different animal. It's a retailer, first of all, and secondly its customer base is generally not overly wealthy -- it consists of bargain seekers looking for deals on bulk items.

It's a similar business profile to Costco, although the two retailers are not equals. Sam's Club took in around $58 billion in revenue last year, essentially flat from the 2013 figure and only a bit higher than the 2012 figures.

Meanwhile, Costco's fiscal 2014 top line was nearly double that of its rival at $113 billion, which was 7% higher than the preceding year's result, and 14% above the 2012 tally.

Further, shaking hands with Sam means only that AmEx cards will be accepted at the warehouses; unlike its collaboration with Costco, the company won't enjoy any kind of exclusivity at the register, nor will it co-brand a Sam's Club card.

So the deal should not, even distantly, be considered a replacement for the Costco arrangement. But I view it optimistically regardless -- it's a sure sign that AmEx can and will eventually fill that hole.

A Chuck Schwab here, a Sam's Club there; AmEx has prestige, clout, and obviously an effective sales effort to win new partners. Companies still want to do business with it, even if it costs them a bit more (AmEx typically charges higher fees than its rivals).

What helps is that the company has developed a range of products that can appeal to various segments of the consumer borrowing market. Its traditional cards, with their perks and rewards in exchange for higher fees, hit the more affluent segments.

Meanwhile it's slowly but surely building its pre-paid cards business. These products are finding their niche with younger consumers, or shoppers on a relatively tight budget.

Profitable recovery
No one gets over a sudden, sharp break-up quickly. Since the day the AmEx/Costco split was formally announced, the card giant's stock price is down by about 4%, while that of Visa is up by nearly 5%.

For AmEx, neither the Charles Schwab deal nor the Sam's Club arrangement moved the needle much on the stock price; investors, it seems, are still stung by the Costco loss (which will hit especially hard at the end of next March, when the arrangement formally expires).

They shouldn't be. It's becoming increasingly clear that AmEx is getting on with its life, and I'd bet that battered share price will rise higher the more effectively it continues to do so.