Persuasive letters can be useful in a variety of situations, including writing to your congressperson about a piece of legislation or to a local merchant to request a refund. When you feel strongly about a subject, it is easy to get carried away by emotion, which can derail your cause. Impassioned language can draw attention, but can often alienate your audience, making them less likely to agree with you. Instead, by using a simple structure and a focused tone, you can improve the effectiveness of your letter.
Write legibly. Use spell check or a dictionary, and proofread your letter for grammar mistakes. Use white or cream paper if you are mailing a letter, or a plain white background for your email.
Open and close your letter professionally. If you do not know the name of the person to whom you are writing, find it out. If you must address your letter generically, at least use a specific title, for example: "Dear Editor," or "To the Store Manager at Safeway No. 21." Close your letter with a simple "Sincerely" and your full name.
Limit your letter to one topic. Effective persuasion is focused. For example, if you are asking a business for a refund, do not include a request for more parking spots as well. If you are writing to a local representative about an upcoming vote, reference it specifically and do not include questions about unrelated legislation.
Support your position with facts. Most people want to do the right thing, and effective persuasive writing is able to convince readers of the "right" action to take. To do this, you need evidence and research. This could be as simple as including your receipt number and the cashier's name when requesting a refund or exchange, or as detailed as outlining why new zoning laws would lower the value of a neighborhood, instead of raise it. Tailor your research to your needs, but be sure and provide enough information to enable your reader to agree with you.
Finally, ask for support. The last paragraph or section of your letter should clearly explain the result you are hoping for. If you want your congressperson to request legislation or vote on a particular bill, state that clearly. If you want your reader to support a local or national charity, give them the full name and the amount you would like him to contribute. If you want your readers to write letters to the editor, tell them the editor's name and when letter's should be sent. Be sure to include your contact information if the reader needs to respond to you directly.