Copywriting is writing copy for the purpose of advertising or marketing. The copy is meant to persuade someone to buy a product, or influence their beliefs.Copywriters (known as continuity writers in brodcasting) are used to help create direct mail pieces, taglines, jingle lyrics, web page content (although if the purpose is not ultimately promotional, its author might prefer to be called a content writer), online ads, e-mail and other Internet content, television or radio commercial scripts, press releases, white papers, catalogs, billboards, brochures, postcards, sales letters, and other marketing communications media pages. In book publishing, flap copy and jacket flap copy describe the brief summary of a book which often appears on the inside of the book's hardcover dust jacket; back cover copy is similar, often briefer text placed on the book's outside back cover; catalog copy is another book summary maintained in a publisher's catalog of published books. Copy can also appear in social media content including blog posts, tweets, and social-networking site posts.