There are also targeted offers for other cards out there.
In addition to the 100k platinum offer, I received quite a few 75k offers for the PRG before I added my first Amex.
From what I've heard, there have been 150k offers for the platinum as well. It required a very high level of spend which is out of reach of most people.
EX 798, EQ 789, TU 784
American Express Platinum (NPSL) || Bank of America Privileges with Travel Rewards Visa Signature - $23,200 CL
Barclays American Airlines Aviator Red World Elite Mastercard - $20,000 CL || Chase IHG Rewards World Mastercard - $25,000 CL
Chase Sapphire Preferred Visa Signature - $12,700 CL || Chase United MileagePlus Club World Elite MasterCard - $26,500 CL
Citibank Hilton Reserve Visa Signature - $20,000 CL || J.P. Morgan Ritz Carlton Visa Signature - $23,500 CL
