In one of the “Dirty Harry” movies, Clint Eastwood quietly says, “A man must know his limitations.”

Very true, and this definitely applies to phone work, whether you’re prospecting, appointment setting, or closing deals.

It’s not a topic I think about all that much, but it coursed through my mind tonight, as I was developing a prospecting campaign that I intend to execute, myself.

I think people have different fatigue settings, but they’re unaware of them.

For me, doing outbound calling for an hour, and I mean a solid one, without breaks, is no big deal. In fact, I just start warming up, getting my phone voice strapped on at the half-hour point.

Two hours, with a quick break in there, is also comfortable.

And that’s it; my current sweet spot, and no more.

So, my campaign will entail two hours of outbound for a month, and I expect it will yield optimal results for me.

I realize it’s not practical to have two hour shifts at my clients’ sites, so at minimum, we schedule four hour sets for their employees. But when I started doing outbound selling for Time-Life Books, we worked only 3 hours per night, and 4 hours on Saturday morning, and it was ideal for college students.

The phone can be a grind, and I’ve never recommended eight-hour shifts. The productivity plummets dramatically, I’ve found after five hours.

You should experiment; especially if you’re an independent businessperson, or you’re in sales and are permitted to allocate your time as you wish.

By the way, if your tolerance level is only an hour or two, it’s not wimpy to acknowledge it, and act accordingly, because, after all, Dirty Harry is right!

Dr. Gary S. Goodman, President of Customersatisfaction.com, is a popular keynote speaker, management consultant, and seminar leader and the best-selling author of 12 books, including Reach Out & Sell Someone® and Monitoring, Measuring & Managing Customer Service, and the audio program, “The Law of Large Numbers: How To Make Success Inevitable,” published by Nightingale-Conant. He is a frequent guest on radio and television, worldwide. A Ph.D. from USC's Annenberg School, a Loyola lawyer, and an MBA from the Peter F. Drucker School at Claremont Graduate University, Gary offers programs through UCLA Extension and numerous universities, trade associations, and other organizations in the United States and abroad. He holds the rank of Shodan, 1st Degree Black Belt in Kenpo Karate. He is headquartered in Glendale, California, and he can be reached at (818) 243-7338 or at: gary@customersatisfaction.com.