Performance Highlighting on the Audience Crosstab quickly gives you a visual cue as to which of your audiences are performing well or poorly against your target audiences. Basically, it helps you understand the data faster.
The Highlight Performance, by default, is enabled. This allows you to quickly see which audiences are over-performing for your target audiences (green highlight) and which are under-performing (red highlight). Target audiences that are in the middle, performance-wise, have no highlights. You can disable this feature by unchecking the box by the feature's name above the table.
Audiences that have an index of 120 or more are, by default, highlighted in green as over-performing. As a guideline, we look for an index of 120 or greater to identify audiences that are prevalent in the crossed audience. Audiences that have an index of less than 100 are, by default, highlighted in red as under-performing. As a guideline, we look for an index of less than 100 to identify audiences that are not important or distinctive in the crossed audience. You can adjust these numbers up or down to adjust the norms for your analysis.
When you save your analysis, these new index numbers will be saved along with it for your username only.