Lester Wunderman — often called the father of direct marketing — died Wednesday at age 98.

Wunderman, who was chairman emeritus and founder of his namesake agency, is credited with innovations like the 1-800 toll-free number and the magazine-subscription card. Wunderman is a member of the DMA Hall of Fame and the Advertising Hall of Fame, and in 1999, Ad Age named him to its "Persons of the Century" list.

Wunderman was so widely admired and beloved in the direct marketing world that Howard Draft, a famed name in the discipline, says Wunderman was "the only guy I'd go to work for. One of the great teachers of all time. There was nobody better."

Draft, now executive chairman of FCB and onetime Draft Worldwide CEO, says he lunched with Wunderman in France every summer after the executive retired. "Lester to me was first and foremost a gentleman, he was a teacher, he was brilliant creatively — ideas just jumped off from him. He, to me, was the god of direct marketing agencies."

Draft recalled a time when Wunderman's name was removed from the door for a short time when the company was called Impiric. "I thought that was the biggest mistake in the history of advertising," he says. "That brand had so much equity ... Wunderman — he was the 'wonder man' of advertising."

Wunderman, a Bronx native, served apprenticeships at several agencies before joining Maxwell Sackheim & Co. in 1947. Wunderman and his brother, Irving, then ran Coronet Advertising Service in New York. They joined forces with direct-mail specialist Cap Pinkster, becoming key figures in the early use of comic books as an ad medium, which became important during World War II as the Army used them for recruiting.

In 1958, Wunderman and his brother founded Wunderman Ricotta & Klein with two other Sakheim employees, account supervisor Harry Kline and art director Ed Ricotta. The shop, one of the first agencies to focus on mail-order advertising, became the largest mail-order agency in the U.S. within a year of its founding. In 1961, it became the first direct-mail agency to be invited to join the American Association of Advertising Agencies, symbolizing the industry's acceptance of mail order.

He also authored two books, "Being Direct," and "Frontiers of Direct Marketing." He was also an accomplished photographer and his images of the Dogon people of Mali are in the permanent collections of the Metropolitan Museum and The Louvre.

Though Wunderman technnically retired from his agency more than 20 years ago, he still regularly came to work at the agency's offices.

Walking down the street with a new suit, a fresh coffee and an early spring in my step.

— Lester Wunderman (@LesterWunderman) March 23, 2012

In November, WPP announced it would merge J. Walter Thompson with Wunderman to create Wunderman Thompson, essentially giving the direct agency top billing.

"For me, who started one little office with my brother and myself down on Union Square, to be the chairman of a company that is global, and practicing a high state of art all over the world, I can't tell you what a revelation, in my lifetime, [it is] to see us go from kind of the horse-and-buggy form of advertising to the internet. It's just miraculous," Wunderman told Ad Age in 2010. "The things we know about people, our ability to make messages more relevant and timely—advertising is just more efficient than it used to be."

Peter Georgescu, chairman emeritus and former CEO of Y&R, recalled a breakfast with Wunderman that he felt epitomized how the man approached business.

"I remember having a breakfast with Lester — we were going to see a client, one of our top clients," Georgescu says. "He stopped me and said, 'So, Peter, what is our cadeau for this client?'" using the French word for "gift."

Georgescu says he was confused and felt it strange that Wunderman would want to bring a physical present to the client.

"And he said, 'No, no, no — Peter, I never go to a client without bringing them a present.' I said, 'So, what kind of present?'" Georgescu says. "He said, 'a business-building idea. There's never a meeting that I've ever had with a client without bringing them an idea.' I put my fork down and I said, 'What a great idea. Let's create one right now.' And we did. After that, I never went to see a client without bringing Lester's 'cadeau.'"

Georgescu says his former mentor and role model was "a real giant."

"It was Lester's instinct — business was always about results in the marketplace," he says. "It meant bringing clients business-building ideas."

Well into his 90s, Wunderman kept a relatively active Twitter profile— weighing in on topics like "Mad Men," the Rolling Stones and, of course, the industry.

I liked that #MadMen. 3.5/5 martinis. That's a lot on a Sunday.

— Lester Wunderman (@LesterWunderman) May 14, 2012

I remember when the Stones played NYC in 1965. Big ruckus. But that kid Mick wrote some toe tappers.

— Lester Wunderman (@LesterWunderman) April 2, 2012

I liked this episode of #MadMen better the first time, when I lived it.

— Lester Wunderman (@LesterWunderman) March 26, 2012

Over lunch, a colleague's young nephew asked me how we tweeted before the Internet. Pneumatic mail tubes and a lot of stationery, kid.

— Lester Wunderman (@LesterWunderman) March 23, 2012