I once gave a shot of alprostadil into the shaft of my penis. The needle was 31 gauge—so small I could barely feel it." It was April 1999, and I was giving my first medical presentation, "Beyond Viagra: The full spectrum of treatments for erectile dysfunction," to fellow internists. I'd acquired expertise in the treatment of ED by moonlighting at an impotence clinic, and I thought it'd be fun to give a talk on the subject. I pitched the idea to the Virginia Chapter of The American College of Physicians, and it was accepted.

Next time a pharmaceutical sales rep for an ED drug visited my office, I suggested that I give talks for his company. At first he was wary, but once he and others from the company heard my talk, they booked me for six sessions.

I enjoyed speaking so much, I decided to broaden my repertoire and try talking about other classes of drugs that I had an interest in—antihypertensives, antibiotics, and antidepressants. To prepare, I did MEDLINE searches, gathered information from specialists, attended seminars, and pooled the experiences of my patients. After I'd determined which meds were the best within the classes, I worked on how to articulate why they were the best.

One said, "Dr. Ferguson, you could sell sand in a desert." I beamed. After all, isn't it important for physicians to be good salespeople? We have to sell patients on the benefits of a healthy lifestyle and on complying with our therapy regimens.

Here's how I work. The first time I give a talk, it takes me 10 to 20 hours to become conversant with the relevant research. Once I've given a talk, there's little need to prepare for subsequent ones.

Where do I find the time? I used to see patients about 60 hours a week; now it's more like 35. Some people ask whether I plan to give up seeing patients altogether. The answer to that is No. If I gave up seeing patients, doctors wouldn't want to hear my presentations. They wouldn't have much confidence in the advice of a doctor who has no practice. The patients I do see benefit from having a physician who spends so much time keeping up with the research.

I receive $1,000-$1,500 for a dinner presentation, and $500-$750 for breakfasts and lunches. Often on days when I give daytime talks, I go on physician calls with the reps, for which I'm paid $100 each. I also do live teleconferences. They're less lucrative but more convenient than in-person presentations. I usually make $350 for a 30-minute teleconference from my home phone.

The bottom line? In 2002, I made about $20,000 from speaking engagements. Last year, I brought in well over $100,000. My revenue from the practice had dropped, of course, but last year I saw a net gain of about $40,000.

Another possible source of income has surfaced as an adjunct to my speaking career: I could share my experience with physicians who are interested in speaking and advise them on how to get started. If I charge $150 an hour, I could make an extra $3,000 a month.

An unexpected perk: Many of my talks are local, so I now have more time to spend with my family. And, pharmaceutical companies pay for my family vacations: Last summer we spent four weeks in Myrtle Beach, SC, and Bar Harbor, ME, where I gave 11 talks and netted about $12,000.

Currently I make presentations for 10 companies on medications prescribed for almost every area of primary care. The key to the success of my presentations is my passion—I speak only about meds I believe to be the best within their respective class. How could I be passionate about a medication that I believe to be second best?

At times, people ask, "Why do you waste yourself working for those damned drug companies?" My quip: "The money, stupid."

Yet the truth is a bit more complicated. Yes, the money is great, and having more time with my wife and four small children is irreplaceable. But a big reason is my idealism—the same idealism that sent me to work for the Peace Corps in Africa, and brought me to medical school when I came back. I believe I'm helping physicians to take better care of their patients.