Postal surveys usually involve mailing self-completion questionnaires to a targeted group of people, e.g. a client’s customers or people living in a certain area.  Some database companies can also supply detailed information on “who lives where”, which can be purchased for market research and therefore make postal survey sampling more precise.

The main advantages of postal surveys are that large numbers of questionnaires can be sent out, at relatively low cost.  The questionnaires can include visual prompts, products for trial, and can be useful for asking the sorts of questions unlikely to be easily answered on the telephone (e.g. where a lot of quantitative detail is required).

The use of the traditional postal service for self-completion questionnaires is being overtaken to some extent degree by email surveying