How would you design a new credit card that is popular AND profitable?

It seems like a lot of cards offering too good to be true rewards don’t last. What is a card that people would like and last for the long term?

One idea could be cards that increases the rewards the more you spend on it.

• No AF
• 1.5% cash back on first $5000 a year
• 2.5% cash back on next $30000 a year
• 1.5% on the rest of spend per year
• Discover or Amex issued so they keep the swipe fees and get closer to breaking even on 2.5% back with a guaranteed profit from the 1.5% back.
• Resets every year

Spend requirements could be adjust but something like may work.