Every paid account has a total number of topics. Each site in your account is allocated a portion of those topics.
In the platform, you can manually topics. But that’s restricted to the number of topics allocated to that site’s inventory.
By default, the allocation is set to more topics than is currently in use. This allows for topics to be added to the site inventory, either manually, or automatically as your site starts ranking for additional keywords.
You can change the allocation as required.
If you set the allocation to less than the number of keywords it ranks for, MarketMuse will use select those terms with the highest Topic Authority.