So what is a copywriter?

A copywriter is anyone who uses words to persuade readers to take a particular course of action. Using the medium language, copywriters encourage readers to make a purchase, give a donation, discover information or anything else that a company or organisation might want them to. A copywriter can work in any medium, from TV advertising and online marketing through to direct mail and outdoor posters. Wherever words are used to sell, the copywriter has a job to do.
There's an important distinction between copywriters who work in-house and freelance copywriters. In-house copywriters are employed by an agency to do copywriting on behalf of their clients, or perhaps by a large company or organisation to work exclusively on their own content. Freelance copywriters work directly with clients they've found themselves, doing their own sales, marketing and administration in addition to the actual copywriting. So freelance and in-house copywriters might have quite different perspectives, and that can impact clients' decisions about where to get their copywriting done. For example, while an agency copywriter might know more about marketing, branding and media buying, a freelance arguably has a sounder understanding of the actual nuts and bolts of running a business.
Copywriters naturally acquire skills beyond simple writing, depending on the areas and media in which they work. Online copywriters, for example, usually benefit from having some understanding of HTML (the language that web pages are written in) and the most common techniques of online marketing and advertising. SEO is a key consideration, and online copywriters have to learn how to write copy that appeals to human readers while also signalling to search engines that a web page is relevant to particular keywords. In fact, the last few years have seen the emergence of specialist SEO copywriters, whose sole focus is copywriting for web pages that are intended to rank highly in search engines.
Other copywriters work predominantly in printed media, such as direct marketing or brochures. They'll have more experience of working with graphic designers, and are likely to have a strong understanding of what works (and doesn't) in terms of layout, colour and imagery. They may work (or have worked) in a marketing agency, collaborating closely with art directors and designers to create the optimum combination of words, design and pictures.
Advertising copywriters specialise in writing eye-catching slogans and relatively short, punchy copy for use in advertisements. Often, they'll offer to create concepts or 'copy plots' - ideas that could be developed into full-blown campaigns or advertisements. Typically, advert copywriters will be highly creative, lateral thinkers. However, they may be less well suited to 'long-copy' assignments, where the client requires a large amount of detailed, factually accurate text with a consistent tone of voice. Such copywriting jobs might be better suited to a specialist B2B (business-to-business) copywriter, or even a copywriter who focuses on particular document types such as white papers, case studies or research notes.