How do I see how many contacts are in a segment and export them to excel?

There may be times where you need to not only see a count for the segment, but export the full segment list.

Simply hover over the segment to get the Edit menu to show. Select 'test' from the drop-down in order to run the query. Once complete an exportable list of all contacts will be displayed. (This process is the same for categories, as categories are a type of segment.)