How to Set Target Groups
Because your subscribers are organized in target groups, you'll need to set a targeting option for your mailings. The Targeting tab displays all target groups in a list/tree structure that is sorted alphabetically.
When you add a story in Mailing Designer, you'll have the option to use Story-Level Targeting (aka “Dynamic Segmentation”). This allows you to send specific stories to a subset of your target group.
Targeted Subject Lines
Targeted subject lines allow you to set alternative subject lines that display to subscribers in specified target groups. Only subscribers in these groups will see these subject lines, so this is a useful tool to help increase your open rate ...