This essay began life as a laundry list of quotes from great copywriters through the ages. But as I mined these writing gems, I realized that memorable advice for writers comes from disciplines that often seem unrelated to the field.

In fact, my all-time favorite quote is gleaned from an artist/inventor/intellectual of the Italian Renaissance.

This collection of quotable quotes and morsels of sage advice govern my writing and my relationships with people as well. We not only sell products and services, but have the power to change people's lives for the better... or the worse.

To paraphrase an old saw – the keyboard is mightier than the sword.

19 quotes from copywriting experts (and just really smart people)

"Simplicity is the ultimate sophistication." – Leonardo Da Vinci

It's impossible to express how much this quote inspires me. Go to my website and scroll to the bottom; you'll see it in the footer. Come to my office; it's on the wall.

This short phrase has had more influence on my writing style than any other. When I find my prose twisted and convoluted, I pull out this quote.

Keep your writing simple, readable and to the point. Leonardo would appreciate that.

"You can have everything you want in life if you will help enough people get what they want." – Zig Ziglar

Zig was one of the most successful salesmen ever; and one of the first that I studied. A top salesman, enthusiastic teacher and honest businessman, Zig Ziglar was proof that business and ethics could co-exist in the same sphere. This quote reminds me that my success as a writer doesn't hinge on one person, product or article.

The more people you can help reach their goals through your writing, the more successful you become.

"When I write an advertisement, I don’t want you to tell me that you find it ‘creative.’ I want you to find it so interesting that you buy the product."  – David Ogilvy

Creativity is fine and dandy. But if the prospect can remember the ad and not the product, you've only entertained and not fulfilled your role as a copywriter.

What was that cute LOL cat selling anyway?

"Decide the effect you want to produce in your reader." — Robert Collier

Copy, a landing page in particular, needs to have one clear message and one specific call-to-action. If you don't know what you want your readers to do... how will you persuade them to do it?

"The man who stops advertising to save money is like the man who stops the clock to save time." – Thomas Jefferson

A penny saved is still just one cent. Or it could be a penny lost. Good copywriting is an essential investment, not an unnecessary cost.

"We have become so accustomed to hearing everyone claim that his product is the best in the world, or the cheapest, that we take all such statements with a grain of salt." – Robert Collier

People see hype coming a mile away. Don't claim it, prove it. Put your readers on a low sodium diet.

"Copy is a direct conversation with the consumer."  – Shirley Polykoff

Don't know Shirley? I'll bet you know one of her most effective promotions: Does she . . . or doesn't she? Only her hairdresser knows for sure (Clairol hair coloring products).

"The consumer isn't a moron; she is your wife. You insult her intelligence if you assume that a mere slogan and a few vapid adjectives will persuade her to buy anything." – David Ogilvy

Any questions? 'Nuff said.

"Poor copy cannot overcome faults or gaps in dealer distribution; it cannot even cash in on the finest dealer setups. But good copy can, and does, surmount many dealer difficulties, making them secondary, and selling in spite of them." – Victor Schwab

The author of 'How to Write a Good Advertisement', Victor Schwab knew the important role that good copy plays, not just in selling the product, but the product maker as well.

"Let us prove to the world that good taste, good art, and good writing can be good selling." – William Bernbach

So many advertisements, especially content marketing pieces, use shock tactics or questionable language to draw attention. For me, if I must use vulgarity to make a point, do I even have one?

"Make it simple. Make it memorable. Make it inviting to look at. Make it fun to read." –  Leo Burnett

Leonardo would like Leo. I know I do.

"You must make the product interesting, not just make the ad different. And that’s what too many of the copywriters in the U.S. today don’t yet understand." – Rosser Reeves

Warning! Homework ahead!

You must carefully study the product or service and discover why it should excite the prospect.

"The most powerful element in advertising is the truth." – William Bernbach

You can't get any plainer than that. Keep honesty in your writing above all else.

"Nobody reads ads. People read what interests them. Sometimes it's an ad." – Howard Gossage

Content marketing can really shine here. To learn how, see the next quote.

"Make your advertising too valuable to throw away." – Sonia Simone

Sonia Simone is the co-founder and Chief Content Officer at Rainmaker Digital. Check out our podcast on how to create better B2B experiences through content.

"A copywriter should have an understanding of people, an insight into them, a sympathy toward them."  – George Gribbin

How can you understand your product's value if you don't understand your prospect's needs?

"Believe me; nothing works as well on the web as deadlines." – Clayton Makepeace

Sage advice for crafting a promotion that has a deadline in the call-to-action – using urgency as a motivator – from one of the highest-paid copywriters of our time.

"Every product has a unique personality and it is your job to find it." – Joe Sugarman

Products with personality? What a concept!

"On the average, five times as many people read the headlines as read the body copy. It follows that unless your headline sells your product, you have wasted 90 percent of your money." – David Ogilvy

This final quote, by the man often call "The Father of Advertising," expresses the absolute importance of crafting "magnetic" headlines.

Think about it next time you're sitting in the doctor's office. During that endless wait to be examined, pick up a magazine to pass the time. What is it that draws you to one particular article over another?

My money's on the headline.

Now, it's your turn

This list of quotes could go on ad infinitum. But I'll stop here.

Why nineteen?

It was at that wise, old age that I first discovered the beauty and power of the written word. And while my focus and the medium have changed over the last three and one-half decades, the love affair has never waned.

So, tell us. What quotes inspire you and fuel your passion for words? What morsels of wisdom guide your copywriting?

Who are your copywriting heroes?