I havent heard in these forums of people trying successfully lowering their interest rates other then through a DMP. CCCs will raise your CL (so you can charge more) but lower your interest rates, I dont think they have much incentive to do so.
I would suspect that most people fall into 2 groups, those who PIF and those who just pay the minimum payment. I was in the latter group.
Except for things like auto loans and mortgages, I think a good FICO player should not worry about interest rates since the goal is to not carry balances or at least not for very long.
If you have to make a major purchase, set a time limit (1,2,3) years and see if a store charge can offer a better rate then a credit card. Sometimes they offer as much as 2 years no interest. If you dont pay in 2 years, watch out of the interest rates.
I still think there are smart options for people if you just shop around.
1/25/2021: FICO 850 EQ 848 TU 847 EX