The biggest opportunity I see for ads on Farcaster right now:

1. At the end of a frame flow, when the frame has nothing left for the user to do, enable the frame dev to serve a *personalized* (and paid) recommendation in the frame
2. Enable frames devs to monetize their frames by adding an ad frame in the frame flow

Shibli Inu

What prevents someone from creating this already?

Wrapped liquid staked Ether 2.0

nothing - hence the suggestion of the opportunity :)

have seen too many ad-cast attempts that imo aren't succeeding/aren't aligned