Some key points about how PROM impacts layer 2 solutions like Optimism:

Governance: PROM token holders can vote on protocol upgrades, parameter changes, and other governance proposals for Optimism. This allows the community to have a voice in the direction of the layer 2 chain.

Security: A portion of transaction fees on Optimism are paid out as rewards to PROM stakers. This incentivizes people to stake and help secure the layer 2 chain through fraud proofs and other mechanisms.

Ecosystem Funding: Part of the PROM token supply is used to fund grants, airdrops, liquidity mining programs etc. to bootstrap the Optimism ecosystem and attract developers/users.

Fee Revenue: Optimism retains a portion of the PROM rewards from fees to fund future protocol development and growth.

So in essence, PROM acts as the governance token that aligns incentives, distributes fees, funds development, and allows stakeholders to have a voice in the direction of the Optimism layer 2 chain. This token model has been adopted by other layer 2s as well to create sustainable ecosystems.