How does Optimism make money?

Could you please explain in detail how Optimism generates revenue? I'm curious to understand the business model behind this blockchain solution and how it manages to make money. What are the key components of its earning streams? Is it primarily through transaction fees, staking rewards, or other means? Could you also elaborate on how these revenue streams are affected by factors like network usage and market conditions? Thank you for shedding light on this aspect of Optimism.