Such a list is based on past purchasing or response mailing list behavior and may include catalog mailing lists, direct mail or direct television buyers, or magazine subscribers. Many companies make money by renting their list out to other mailing list companies. The idea behind using such a list is that past purchasing behavior is the best indicator of future mailing list purchasing behavior. In other words, if someone responded to a direct TV ad for jewelry, chances are better that they'll respond to another offer for jewelry.
List brokers often add additional selections mailing list for an extra fee, such as 3 month buyers. This allows you to target people who have recently bought such an item. Again, based on years of data from many industries, these are people most likely to mailing list respond again to similar offers, which is why direct marketers seek out such lists. Compiled lists: Compiled lists are mailing list created or compiled from public records. Such lists used to be based on DMV records but now are mainly typed into computers directly from telephone books.
Sometimes public data such as census data mailing list is appended to the list, providing some ability to sort by income and other factors from census data. Compiled lists are the least expensive but also the least likely to respond to specific offers. Going mailing list back to the jewelry example, you may rent a compiled list of people living in a high income zip code, thinking that they mailing list are likely to buy jewelry from a direct mail order catalog. But you have no way of knowing from the compiled list if such people are comfortable shopping online, by phone or from a catalog.