All of the standard Marketo dimensions are included, but you have the option of adding up to 10 custom dimensions. Custom dimensions consist of segmentations and program tags. Here’s how to add them.
Admin Permissions Required
Custom dimensions cannot be deleted or replaced, so choose your 10 carefully.
In Email Insights, click the gear icon in the upper-right of the page.
Click the + next to Add dimension.
By Audience: Displays all approved Segmentations (from within the Database)
By Content: Displays all Program Tags