The American Express Centurion Card

Sources:
https://www.cnbc.com/select/average-credit-card-balance-by-state/

https://thepointsguy.com/guide/amex-centurion-black-card/

https://en.wikipedia.org/wiki/Centurion_Card

https://www.snopes.com/fact-check/black-american-express-card/

http://www.luxuryplastic.com/wall-street-journal-5131988-an-american-express-black-card/

http://www.luxuryplastic.com/black-card-history/

https://www.cheatsheet.com/entertainment/jerry-seinfeld-claimed-he-is-responsible-for-the-invention-of-the-american-express-black-card-is-it-true.html/

https://www.forbes.com/advisor/credit-cards/reviews/centurion-from-american-express/

https://www.americanexpress.com/idc/en/benefits/the-platinum-card/global-lounge-collection.html

https://www.americanexpress.com/us/credit-cards/card/platinum/

https://www.businessinsider.com/how-to-fly-free-forever-put-170-million-on-your-amex-2015-11

https://www.dailymail.co.uk/femail/article-9658459/Amex-Centurion-card-members-reveal-outlandish-requests-theyve-24-7-concierge.html

https://thepointsguy.com/guide/credit-card-concierge-request/

https://onemileatatime.com/guides/amex-centurion-card/

https://www.cntraveler.com/story/american-express-black-card-perks-fees