Marketplace Marketing Strategy

Job ID: 30658453

Budget: $250 – $750 USD

I have marketplace that will serve mainly Shopify merchants and other platforms merchants as well. The main feature the marketplace will allow merchants to provide their customers to sell on their page within the marketplace.
Currently the marketplace is final stage of development and I need a help to develop the marketing strategy since the marketplace doesn't have any merchant.
What's the best commission rate?
What should be the commission rate at start ? When should be increased?
Is there any marketing tools that help attracting merchants from Shopify and platforms such Magento?

The freelancer must provide a strategy with a case study that shows comparison against other small and large marketplaces. In addition, the freelancer should have an experience in marketplace and e commerce marketing.
Other detailed information will be shared upon agreeing on assing the project.