Who a send goes to
Several segments in, segments back out, and a cutoff for people who have just bought.
EmailAn audience is three things: what to include, what to take back out, and whether to skip recent buyers. Includes are added together — anyone in any of the segments you tick is in. Excludes are subtracted afterwards and always win, so a person on both lists is left out. That order is what lets you say the thing you actually mean: “everyone on the list, except staff, except anyone who ordered this week”.
The recent-buyer cutoff is separate from the segments because who bought lately changes every day; a segment would be stale by the time you sent. Set it to the number of days that feels rude to ignore — 7 or 14 for most shops — and anyone with an order inside that window is skipped.
The count under the picker is the answer after all three rules, and the results page names every rule that removed somebody: without an email, unsubscribed, duplicate address, in an excluded segment, or had just ordered. A number smaller than you expected should always explain itself.
Sends made before this existed had one segment and still read correctly — a single segment is simply an include list of one.