You have it slightly wrong - I guess that's why you think it's a ponzi. In Churning you're not paying anyone or forcing any to open up bank accounts to get the

You have it slightly wrong - I guess that's why you think it's a ponzi. In Churning you're not paying anyone or forcing any to open up bank accounts to get the sign up bonus. You're signing up to bank accounts and credits cards yourself, getting the bonus, and then leaving the service onto the next one. --- In Crypto, you "sign up to the service" which can mean a whole variety of things. For example for an AMM it could mean providing liquidity on the USDC - USDT pair. As a marketing incentive, you start getting a "bonus" that is in the project's own token. Every time you earn some of that token, you take it and sell it on the open market for more USD. There are actually even "auto-compounders" that do this for you. This is yield farming. -- The point here is that in both cases you take something that is meant to be a marketing incentive, and make it into cashflow for yourself.