Image: Credit card © Burke, Triolo Productions, BrandX, Getty Images

What if what was in your wallet really did make you a better person -- or at least perceived as one?

The closest thing to such a notion may be the American Express Centurion Card, also known as the Black Card.

Released in 1999, AmEx has created an aura of mystery and power around this rectangle of sturdy titanium.

Although American Express is decidedly discreet about the details of membership, this is what we do know:

  • The Black Card has no credit limit.
  • Cards are issued by invitation only.
  • One of the criteria considered for an invitation is annual credit card charges. Those interviewed for this story say the threshold for invitation has been lowered from $1 million to $250,000 in recent years.

What is clear is that the one-time $5,000 initiation fee and annual $2,500 membership do come with unique perks, including airline and hotel upgrades, and a personalized concierge service that helps with travel and restaurant reservations as well as shopping procurement -- benefits many holders say are the Black Card's true value.

But this hard-to-get credit card, with its unusual color and hefty metal weight, does more than ensure access to airport lounges. As a symbol of wealth and power, it is known to provoke awe in those who covet it.

We interviewed some Black Card holders, as well as those who have been in the card's presence, about the privileges only membership can buy.

Want great service? Mention the card

Social-media entrepreneur and media consultant Peter Shankman says that while the concierge service has saved him in many personal and professional pickles, he flashed the titanium just once in an effort to get VIP service. It worked.

Shankman was in desperate need of a new suit and was browsing in an Armani store wearing his usual uniform of T-shirt and jeans. "No one paid me any attention. It was right out of 'Pretty Woman,'" Shankman says. "Finally, I said loudly: 'Never mind! I'll take my Black Card and go to Prada!' Within a minute, eight sales guys were there ready to help me."

Broke, but he won't give up his Black Card

Not all stories are so entertaining. Aylin Unal says a longtime friend finally qualified for a Black Card after coveting one for years. He has made a point of showing it off frequently.

"Even if he charges $3, he makes sure to put the card in front of everybody," Unal says. "He carries everything on a money clip, and the card is always on the outside."

In recent years, the friend has found himself in six figures of business and consumer debt and had his electricity turned off a few times for nonpayment, Unal says. Nonetheless, he has thwarted his accountant's and attorney's advice to declare bankruptcy, because doing so would mean he would lose the Centurion.

Unal asked her friend why he continues to pay the pricey annual fee when he does not take advantage of the card's travel perks. "He said it was worth it for him to get good treatment at the valet or a bar," she says. "It's really sad that at this point in his life he doesn't think better of himself."

Make the wait staff fawn over you

Other cardholders' friends get a kick out of the over-the-top service the card can prompt. Donna Wheeler has a friend who owns a Centurion, but only because the friend's husband works for American Express, not because she's a high roller. Wheeler says the power of the card is evident in restaurants, where the wait service may be mediocre until the card is handed over with the bill.

"Then they are fawning over us, saying, 'Oh, I hope you had a good visit!' We just look at each other across the table and crack up laughing," Wheeler says.

When charm fails, flash the card

Edward Ip, the owner of an information-technology consulting firm, is another cardholder who prefers to be discreet.

"The people the card attracts are not the people you want to attract," he says. "Your close friends know who you are and what you do, so they're not surprised or shocked to see it." That said, "it is a great way to get the bartender's attention."

Ip says his card can be credited with the bottle of champagne that was sent to his table the first time he visited the famed New York restaurant 21 Club, as well as an upgrade at a Beverly Hills hotel. "Charm works really well to get upgrades, but in these cases I got the perks before I demonstrated my charm," Ip says.

The Black Card as a pickup tool

John Mahdessian, the owner of a high-end fabric cleaning service in New York, has had the card since 1999. He says he sought out the card by intentionally charging $1 million on his AmEx that year with the sole aim of being invited. Mahdessian says the card exudes the type of status he seeks.

"I'm the most eligible bachelor with a spotless reputation," says the fortysomething New Yorker. "I like to use it to impress the ladies, and they certainly are very inquisitive about it. I think that it shows that you are not only responsible with your money but that you have arrived financially in your life and in your career.

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But not all women are bowled over by the Black Card. Liz Grimes encountered one when she was a waitress in college. She waited on a couple in their 20s who came in for lunch. They were low-key and friendly, and, after chatting with Grimes for a while, the guy handed over his Black Card to pay the bill. Grimes and her colleagues were impressed.

"We were all wondering how someone so young could have possibly gotten their hands on one of these. Was it his parents? Maybe his job?" Grimes recalls. Imagine her surprise when she picked up the signed receipt to find a $30 tip on a $30 bill -- and a phone number, smiley face and note that read, "Call me."

"My friends insisted that I call him for the pure fact that he paid with the Black Card," Grimes says. She refused. "Just because this guy obviously had money, I was not going to sacrifice my morals and get involved in this situation."

Or, as Mahdessian says: "Just because you charge $1 million doesn't mean you have $1 million."

This article was reported by Emma Johnson for CreditCards.com.