Maybe you are seeing a response from the bank’s there, maybe it’s unrelated. It’ll be interesting to see how they do react once Monzo gets to a significant size (1m+ users, by the middle of next year) & I can see why cashback could be part of that.
If that’s what you’re looking for, check out Tail. They’re offering the sorts of %’s that you’ve mentioned for the retailers that they’re working with -
If it was that easy for the bank’s to secure big cashback deals, I don’t see why they wouldn’t have done so before now.
And to be honest, it’s Monzo’s ability to provide a superior user experience that’s one of the main threats to the bank’s. Something that I believe they’ll find much more difficult to replicate.