Jim Ackerman explains how it worked.

If you're holding private sales and they're not working as well as you'd like, marketing specialist Jim Ackerman says its time to change up your marketing.

Most jewelers promote these events via Facebook, email and postcards. But you might want to ditch the postcards, he says.

In the video below, Ackerman shows how one jeweler achieved a superb 12 percent response rate using a well-crafted two-page letter. As a result, the store did $80,000 of business in two days.

Take a look: