[SPIKE] Look into adding a flat transaction fee to forwarder contracts

[vmichalik]

• Slack thread https://superfluidhq.slack.com/archives/C04V40RFJQ7/p1691402983239459 from @fran
  • I’d like us to run a spike on this, exploring potential issues that may arise so we know if it’s a viable way forward.
  • If we were to enable fees, even small ones, then any “noise generation” campaign also becomes a profit opportunity, which would make for a positive outcome, and make us less weary of occasionally subsidizing sentinels
  • If we decided to be more aggressive, we may also consider disabling callAgreement altogether (while leaving callAgreementWithCtx)
• Ideas
  • Figure out the complexity and risks/concerns with adding a flat fee to interactions (createFlow, updateFlow, etc), calculate cost delta to end users
  • Compare with options for ongoing fees (subscription-type fee model)
  • May be strongly aligned with account abstraction (since fees and gas are already blended)
    • We could consider taking gas and protocol fee together in the payment token or a stablecoin
• Concerns
  • AA is still early and supporting EOAs and Safes are still priority 1 and 2, not exactly clear how this will play out
  • Ongoing fees align us with payment processors in ways we’ve been trying to avoid in sales and marketing
  • We should aim to not require additional transactions to the end-user flow
  • Avoid scenarios where user sending 5 tokens and receiver gets 4.77
• Examples
  • Charging per tx is already somewhat palatable (people expect to pay gas cost), Sound.xyz and Zora add a 1$ flat fee per tx and generated $millions of revenue off large scale free mints
• Initial investigation Spike
  • Propose an approach to paymaster/gas abstraction integration to Superfluid Subscription flows that would a) simplify end user flow and b) provide more dynamic options for gas + protocol fee
    • Review strategy with wider team before implementing PoC

[philipandersson]

Hey team! Please add your planning poker estimate with Zenhub @0xdavinchee @d10r @ngmachado