Each Ignite plan allows you to link as many Amazon accounts as you like! Ignite plans are simply based on your total monthly ad spend, across all connected marketplaces. This means that you can add as many marketplaces as you want!
If you think you need a larger plan that supports an ad spend over $25,001, please let us know! You can reach out to our support team at firstname.lastname@example.org so we can find a larger plan that may work for you!