One million Plat card holders (counting both business and personal cards) can hardly be described as "exclusive", but it's still a very small fraction of the total number of AmEx cards out there (25-30m in the US).

I first got Plat in 1992 when it was by invitation only (I loved the app, too -- all they wanted was my SSN and signature, I guess because they had enough payment history from me already). If I remember correctly, the invitation letter said that Plat offers were extended to the "top 2%" of AmEx card holders.

So even with all the marketing of the Plat in the past ten years it looks like it still accounts for only 3% of AmEx cardholders. And if you don't include the business card, which didn't exist in 1992, it's about 2.5%.

I find this surprising given the "promotion" of Plat, so if anyone can run the numbers differently for me, I'd be interested.