A letter of introduction is a simple yet effective marketing strategy for freelancers and small businesses, which introduces them as professionals and their work to potential new clients. It differs from a pitch in that it doesn't propose a specific project or deliverable but rather serves as an introduction to build relationships. The LOI typically has five parts: an opening, introduction, description of services, samples, and a call-to-action. A letter of introduction can be used by freelancers in various industries and is not limited to writers alone. It's essential to personalize the opening, keep it concise, create separate templates for different industries, choose samples carefully, and tailor them to the client's needs and audience. The goal is to give good value rather than sending out a high volume of emails. With its ability to practice an elevator pitch, work on lead generation, and get a name out there, a letter of introduction can be a valuable marketing tool for freelancers and small businesses.