Inviolable List Principles

5. When selecting lists, look for the following:
- descriptions of those on the file (e.g., subscribers, members, buyers, donors, expires, former buyers);
- affinity (e.g., based on consumer profile, previous list history, or a subjective extension of interaction or experience);
- source used to acquire the names (e.g., direct mail, space ads, radio, television);
- recency of acquisition (e.g., hotline names);
- frequency (e.g., multibuyers); and
- average order size.