One of my freelance gigs is editing a weekly newsletter. As I was putting together this week's issue, I found an essay in my slush pile that I wanted to use. If I could have contacted the writer quickly, I might have published his essay.
But I couldn't. Neither his manuscript nor his cover letter included an e-mail address. Neither his manuscript nor his cover letter included a telephone number.
I tossed the manuscript aside. I didn't have time to write a letter and expect a response in the half-day I had before deadline, and I wasn't about to waste time looking for a telephone number that might prove to be unlisted.
The writer lost a sale because I couldn't contact him.
Maybe it isn't a permanent loss. Maybe I'll have time later in the week, or next week, or the week after, to write him a letter and await his response. Or maybe I won't. Maybe the manuscript will languish in the slush pile until I get tired of looking at it and I'll just shove it in the return envelope. He may never know how close he was to making a sale or how his own failure to provide complete contact information may have lost him the sale.
I've been on the other side of this quite often--twice in the past month, even--where editors contacted me (one by e-mail and the other by phone) to tell me they wanted to use something immediately. They found me. I said "yes." I made the sale.
My advice: Always, always, always, include complete contact information on your manuscripts. Don't lose sales because you forgot to tell an editor how to reach you.