Lately I've been asked by several prospective clients to create or duplicate another company's marketing materials (e.g., brochures, training manuals). Not only are there legal and ethical issues involved (copyright, for example), but each business is as unique as its owner(s) and their marketing materials should be branded to reflect that uniqueness - from the layout, logo and design all the way down to the copy.
If you are creating or redoing marketing materials for your business, explore the materials of your competitors to see what elements you like and what you don't like. But when you sit down with your graphic designer and copywriter, make sure the materials reflect YOUR BUSINESS, not someone else's!
Dana