1) Like some ad campaigns 
Mail designed to motivate readers to respond directly to senders with a purchase, donation, or other action.
A means of marketing whereby consumers are sent correspondence to their home.
A form of advertising that allows companies to contact you directly with information about products and services that may be of interest, using mail addressed to you personally.
Marketing communications delivered directly to a prospective purchaser via the U.S. Postal Service or a private delivery company.
[n] - advertising sent directly to prospective customers via the mail
Delivery of an advertising or promotional message to customers or potential customers by mail.
a direct marketing technique involving the delivery of promotional material to named individuals at their homes or organisational premises.
Often described as 'salesmanship in print'. Direct mail is a personally addressed advertising piece sent through the post.
noun advertising sent directly to prospective customers via the mail
Delivery of advertising or promotional material to potential customers by mail.
mail, usually consisting of advertising matter, appeals for donations, or the like, sent simultaneously to large numbers of possible individual customers or contributors. Abbr.: DM