Many fund raisers get frustrated when their carefully crafted direct-mail appeals create lower-than-expected results.

In many cases, charities blame the letter for the poor response.

But Sandy Rees, a fund raiser who works with nonprofit groups in Knoxville, Tenn., says the real culprit for poor direct-mail results often lies elsewhere.

Ms. Rees, writing on the Get Fully Funded Blog, says the letter accounts for only about 10 percent of a direct-mail appeal’s effectiveness.

The most important factor in getting results, she says, is the mailing list.

“The list you use to mail to will make or break your appeal,” Ms. Rees writes. “After all, if you don’t mail to the right people, it doesn’t matter how good your letter is.”

She estimates that the mailing list accounts for about 40 percent of an appeal’s success.

Other important elements include the timing of a mailing (20 percent), the offer (20 percent), and the envelope (10 percent).

Do you agree with Ms. Rees’ assessment? Are factors like the mailing list and the timing of an appeal more important than the message carried in the letter?

Click on the comments link below this post to share your thoughts.