Master Internet marketer Alex Mandossian recently warned his readers to avoid a common mistake: buying courses sold by "gurus" who don't practice what they preach.

He's right. Don't buy courses from gurus whose reputations are based on work they did years ago – but are no longer active in the field.

As Alex points out, by following the guru's advice, you risk doing the wrong stuff -- stuff that might have worked 2 years ago but doesn't work any longer.

I agree. There are a lot of people teaching disciplines in which they were skilled practitioners once.

But then they were tempted by the Force, went over to the dark side, and decided they could make more money teaching than doing.

Now writing, teaching, and speaking about their topic is all they do today -- they stopped being active participants in their markets years ago.

And for the eager hordes who buy their info products, that's a problem.

Why? Because these gurus lack a critical element needed to be a great teacher.

Namely, ongoing feedback on what's working ... current experience that active practitioners get every day but mere teachers don't.

I call gurus who stopped practicing their profession and now just teach it "big hat, empty cattle" gurus.

Sure, many have great war stories.

But when it comes to successfully tackling today's challenges ... they haven't a clue. And their students often pay the price for teacher's ignorance.

I feel so strongly about this that my advice is to always look for courses from gurus who are also active practitioners in their field.

For instance, I admire successful professional speaker MA, because he once wrote that meeting planners should never hire speakers who are only speakers and book authors ... but are no longer working in the field they teach.

MA practiced what he preached: while maintaining a busy calendar speaking on running a business, he also ran two insurance agencies.

For this reason, I have less admiration for Peter Drucker and Tom Peters who together represent two generations of management gurus.

Both made their reputations by writing books. But neither was a CEO or held any other high-level management position with the large corporations they now feel they are qualified to advise.

The flavor of management guru I prefer is Jack Welch.

Yes, he wrote a couple of best-selling business books.

But unlike Drucker and Peters, Welch was CEO GE – and is widely recognized for having been one of the more effective managers in corporate America.

During his two decades as CEO of General Electric, Jack Welch grew the company's market value from $12 billion in 1981 to approximately $280 billion in 2001.

Businessweek once said, "Welch has become the gold standard against which other CEOs are measured ... he is the celebrated chairman and chief executive of GE, the company he has made the most valuable in the world."

Before you object that Welch isn't an active CEO, keep in mind that he was CEO of GE – not Joe's Widget. So even though he resigned in 2001, I give him a big pass.

Some of my subscribers may object that I am the very type of guru I dislike – a Peters instead of a Welch, because of the dozens of marketing books I have written.

They may be unaware that I have been writing direct marketing copy for 35 years and continue to do so today, with no sign of slowing down.

Today I am still at the PC working 12 or more hours a day, 5 days a week, plus additional hours on the weekends.

If such were not the case, I would feel as if I were ripping off clients who engage me to give seminars, publishers who give me contracts to write books, and you, Dear Reader, who spends time and (for some of you) money on my advice.

Do you agree?