Which pulls the best response, a postcard, a self-mailer or a letter? The answer, you¡¯ll be irritated to know, is clear. It depends.

The success of your mailing depends on who you mail to (your list), what you promise (your offer), when you mail (your timing), and what you mail (your format and creative). Here are a few questions to ask yourself to decide which format is likely the best one to use for your next mailing.

Letter\rDoes your sales message need to come from one person by name? Does it need to be addressed to a person by name? Is privacy or confidentiality a concern? Then a sales letter inside an envelope is the way to go.

Postcard\rIs your sales message short and simple, and designed to motivate your prospect to visit your website to hear your full pitch (and place an order)? A postcard is a good option.

Self-mailer\rDo you need to illustrate your sales message while keeping printing and mailing costs down? Then try a self-mailer (a document that mails without an envelope, such as an 8 ? x 11 sheet of card stock, folded once on itself and sealed with a tab).

Classic direct mail package\rDo you have things to say that do not really fit in a letter (technical specifications, for example)? Is your sales message longer than 600 words? Does your prospect need to mail back a check or order form? Then a classic direct mail package is your best choice, consisting of a mailing envelope, letter, brochure, business reply card or order form, and business reply envelope.

Dimensional mailer\rDo you need to reach C-level executives in Fortune 500 companies? Executives who have mailroom staff and executive secretaries who screen their mail? Then a dimensional mailer may be the most effective way to reach their desk with your sales message. One firm recently mailed a portable DVD player in a high-end box, and enclosed a sales letter explaining that the executive could get the remote control unit (without which the player did not work) by meeting with a sales rep from the company who mailed the package. The response rate was high.

Catalog\rDo you have a lot to sell? Do you need to show the color, shape or quality of your product? Mail a catalog.

Unaddressed flyer\rDo you have a message that needs to reach everyone in a given geographic area, such as a business park, for the least amount of money? Consider mailing a simple 8 ? x 11 sheet with copy and design on one or both sides.

Email\rDo you have a short sales message for your existing customers? Send them an email (with their permission, of course).

Buckslip\rDo you have a short announcement for your existing customers? Do you need to remind them about something? Include a buckslip in your next mailing. A buckslip is a slip of paper the size of a dollar bill, with copy and graphics on one or both sides, that is enclosed in a mailing envelope with other materials).

Alan Sharpe is a business-to-business direct mail copywriter, lead generation specialist and publisher of ¡°Sharpe & Direct: The B2B direct mail marketing e-newsletter.¡± Receive a free report when you sign up at http://www.sharpecopy.com