Join our Waitlist for Expert Advice!

The Only True Way to Become a Marketing Genius Whatever the strategy, whatever the product, whatever the decision, test it and let the the results guide you to success.

By Perry Marshall

Opinions expressed by Entrepreneur contributors are their own.

Hero Images |Getty

There are a ton of gurus, books, courses, seminars, coaching programs etc. for marketers, all of them claiming to make you a genius, to deliver the All Pervasive, Hidden Secrets of the Marketing Universe.

A few of them are actually good. And I only endorse people whom I can fully recommend as head and shoulders above the rest of the crowd.

But there's the old saying, "you can't learn to ride a bicycle at a seminar." And it really doesn't matter what aspect of life we're talking about, there's a huge, enormous difference between learning from a guru and actually doing it.

The real, bottom line truth about really talented marketers and anyone else comes down to one word. Just one.

The word is: TESTING.

If you don't test -- if you don't develop an idea, run it up the flagpole and see who salutes, with hard numbers and percentages -- you really don't know anything.

If you DO test -- you know everything. And nobody can argue with you. If they do argue with you, you don't care anyway.

Related: Market Testing

That's all there is to it.

The questions one can ask, or debate, are endless. Does long copy work or is short copy better? Should I have a sales letter website or a traditional one? Should I price this at $500 or $1000? Should I use a soft-sell approach or is hard-sell better?

The answer to each and every question is, test.

One of the reasons I quickly became obsessed with Google AdWords is the fact that you can test things with such speedy precision. Split test two ads and measure the response to a tenth of a percent. Split test two landing pages on your website and see which one gets more orders or leads. Turn the test on, and turn it off -- instantly.

Beware: When you test, you need statistically significant results. Now we could get a math professor to wax eloquent about this, but essentially you need enough trials to have reliable numbers. If you flip a coin four times and it comes up heads all four times, it doesn't mean that there's no tail.

There's still a 50 percent probability of being heads or tails, you just happened to get four heads in a row.

A simplified but useful rule for testing is: You need to get 30 or more responses, under a consistent set of conditions, in order for your numbers to be accurate within five percent.

So if you're split testing two pay-per-click ads on Google, one got five clicks and the other got 10, you really don't know which one is better yet. The luck of the draw could be favoring the one. But when one gets 30 and the other gets 50, you're pretty certain. Same is true with direct mail, or responses to a web page, or email, or whatever. At least 30 responses for each thing you test.

Related: 4 Steps to Knowing What Your Customers Want Better Than They Do

Testing is cheap and easy.

Testing used to be a lot harder than it is now. Read Scientific Advertising, written in 1918 by Claude Hopkins. He talks about taking months to run ads in newspapers, collect coupons from retail stores, and assess the success of campaigns. Now you can send out a few thousand emails, split between one offer and another, and you know within a few hours which offer is better.

Testing used to be very expensive and take weeks or months. Now it's cheap and it takes hours or days. There's no reason why you can't know anything you want to know with inexpensive testing! And no reason to spend millions of dollars developing an idea that nobody will buy. Sales people look at rejection as failure, but direct marketers see it as only a test. Which way do you want it?

Testing weeds out those bad ideas, and leads you to the good ones. The answers will always surprise you.

Related: Why Split Testing Is the Best Way to Prevent Wasting Marketing Money

Perry Marshall

Author, Sales and Traffic Expert, CEO and Founder of Perry S. Marshall & Associates

Perry Marshall is the president of Perry S. Marshall & Associates, a Chicago-based company that consults both online and brick-and-mortar companies on generating sales leads, web traffic and maximizing advertising results. He has written seven books including his most recent, 80/20 Sales and Marketing (Entrepreneur Press, 2013), Ultimate Guide to Facebook Advertising (Enterpreneur Press, 2014), Ultimate Guide to Google AdWords (Entrepreneur Press, 2014), and Ultimate Guide to Local Business Marketing (Entrepreneur Press, 2016). He blogs at perrymarshall.com.

Want to be an Entrepreneur Leadership Network contributor? Apply now to join.

Side Hustle

At 16, She Started a Side Hustle While 'Stuck at Home.' Now It's on Track to Earn Over $3.1 Million This Year.

Evangelina Petrakis, 21, was in high school when she posted on social media for fun — then realized a business opportunity.

Health & Wellness

I'm a CEO, Founder and Father of 2 — Here Are 3 Practices That Help Me Maintain My Sanity.

This is a combination of active practices that I've put together over a decade of my intense entrepreneurial journey.

Business News

Remote Work Enthusiast Kevin O'Leary Does TV Appearance Wearing Suit Jacket, Tie and Pajama Bottoms

"Shark Tank" star Kevin O'Leary looks all business—until you see the wide view.

Business News

Are Apple Smart Glasses in the Works? Apple Is Eyeing Meta's Ran-Ban Success Story, According to a New Report.

Meta has sold more than 700,000 pairs of smart glasses, with demand even ahead of supply at one point.

Money & Finance

The 'Richest' U.S. City Probably Isn't Where You Think It Is

It's not located in New York or California.

Business News

Hybrid Workers Were Put to the Test Against Fully In-Office Employees — Here's Who Came Out On Top

Productivity barely changed whether employees were in the office or not. However, hybrid workers reported better job satisfaction than in-office workers.