The amount is suspiciously close to the standard frontend fee, around 0.75%

Is Rainbow collecting roughly a 5-6 USD fee on a 750 USD swap? Is this standard behavior?

show of hands: how many of you know what you're paying in swap fees?

Yes and most people look away https://farcaster.xyz/nonlinear.eth/0x0edac40b

yea... gas fees, builder fees (aka MEV, slippage), validator fees (share of MEV), frontend fees

arguably indirectly AMM liquidity fees (absorbed by builder fees)

but I think it's fair to call all of these "swap fees" as far as the end-user is concerned

The Farcaster formerly known as Kchamp. Books, beats, bodybuilding, bright ideas and beautiful things.

katherinechampagne.com

relevant sub-sub-sub-thread: https://farcaster.xyz/shazow.eth/0x888afd53