Why do so many advertisers pull ads just as they're beginning to work? Or mail a direct marketing package only once? Most prospects have to be exposed to your message - not necessarily in the same medium - multiple times before they're likely to respond to it.

Here's a rundown of current thinking on repetition and frequency in marketing communications:

• Media researchers have long held three exposures to be the "effective frequency" for an advertising message to sink in. But depending on your "reach"-the percent of the audience actually exposed- you clearly have to run an ad or broadcast spot much more than three times to have any effect.
  
  
• The author of Guerrilla Marketing, Jay Conrad Levinson, writes that your average prospect must be exposed to various forms of your marketing nine times before becoming a customer. And because his rule of thumb is that you miss your prospect two out of three times, it takes 27 attempts to achieve those nine exposures.
  
  
• Industrial advertisers in business publications are better off choosing frequency over ad size and color when their objective is to generate inquiries or direct sales. When image or positioning is the objective, size and color are better investments.
  
  
• In direct mail, a repeat mailing to the same list within 30 days will pull 40 to 50% of the first mailing.

Everything takes time. Be patient, persistent, and consistent for best results.

Robyn Sachs is the president of RMR & Associates, a full-service advertising, marketing and public relations firm based in the Washington metropolitan area that specializes in the high tech industry and is known nationally for its innovative campaigns. She can be reached at rsachs@rmr.com. The Marketing Advisor is published quarterly. We welcome yolur comments or questions.