(Bloomberg) — American Express long held a special place in the credit-card continuum. It wasn’t just any piece of plastic—to possess one you had to pay your balance every month as well as a notoriously painful annual fee. But laying it down on the counter became a gesture of wealth by the lucky cardholder, and there was the ultimate manifestation of success, its famous Black Card, to aspire to.

Those days may be over. With rivals such as Chase and its Sapphire Reserve card angling for a piece of its luxurious patch, Amex has found itself on the defensive. Now, the granddaddy of charge cards is fighting back.

The first order of business has been persuading more of America’s 27.9 million small businesses to accept it as payment, eventually achieving parity with Visa Inc. and Mastercard Inc., a goal the company says it will reach by 2019.

Bloomberg News
Bloomberg News

Many of those mom-and-pop businesses—florists, drycleaners, liquor stores—have been reluctant to pay for the privilege of having that sticker on the front door saying “American Express Cards Welcome.” But in the past two years, Amex has worked to add 1.6 million of them to its network, a strategy it says is now bearing fruit: Almost 75 percent of Amex cardholders say they have used their card at a small business.

Howard Grosfield, executive vice president of U.S. consumer marketing, said that the company has “crossed an enormous and accelerated threshold in terms of the number of small merchants that are accepting.”

“We’ve really doubled down over the last couple of years,” said Grosfield.

After deciding last year to part ways with its biggest co-brand partner, Costco Wholesale Corp., which accounted for 10 percent of Amex cards in circulation, the company has been looking for new revenue streams. But as banks and rival networks move aggressively to wrest away other Amex partnerships, Chief Executive Officer Kenneth Chenault vowed to avoid making less favorable deals just to beat them back .

Instead, the card company has been working assiduously to woo mom-and-pops to its side. Amex declined to disclose the total number of merchants that accept its cards, but the company did say that, over the past two years, it’s added more than 35,000 San Francisco-area businesses, 85,000 New York-area businesses, and 40,000 Chicago-area businesses to its network.

For those small retailers still on the fence about accepting Amex, the card issuer said on Monday that it’s launching its largest rewards program ever to sweeten the deal. Beginning this week and continuing through the end of the year, card members can earn double rewards when they shop at eligible small businesses, the company said in a statement.

For individual cardholders, the promotion will apply to the first $100,000 in eligible purchases. For small business cardholders, the promotion will apply to the first $250,000 in eligible purchases. The promotion is Amex’s largest and longest rewards program ever, the company said.

The rich rewards come as rival card issuers look for footholds in the burgeoning luxury credit-card market, which has long been Amex’s playground.

In August, the introduction of Sapphire Reserve brought with it rewards that include a sign-up bonus of 100,000 points, triple points on travel and dining, airport lounge memberships, and credits that offset the card’s whopping $450 annual fee. So many people signed up for the card that the bank ran out of the cards after about a week.

On the back of the Sapphire Reserve’s success, JPMorgan Chief Financial Officer Marianne Lake said on Oct. 14 that the bank has plans to continue investing in its card business to build market share. Citigroup Inc., the world’s biggest credit-card lender and new issuer for Costco’s retail card, said it has plans to grow its card business in a separate conference call that day.

“There’s certainly a competitive dynamic in the marketplace that’s focusing on rewards points,” Amex’s Grosfield said. But, for Amex, “what’s so different about this is that this is building on a legacy” of the company’s commitment to small business owners, as opposed to just a play in the frenzied luxury rewards space.

Chenault laid out his company’s plans to match acceptance with Visa and Mastercard in March. At the time, the 65-year-old CEO said the decision to pursue small businesses would prompt a decline in the company’s discount rate, a measure of the fees Amex charges merchants. As of June 30, Amex’s discount rate had slipped to 2.43 percent, from 2.49 percent a year earlier.

“This represents a major shift in our strategy,” Chenault said in March. “This will impact our revenue growth in the near term, but over time a larger merchant base will translate into higher billings, improved perception of coverage, and great scale and relevance.”

That, he said, is “a trade-off for growth we’ve chosen to make.”