Shari Cohen, one of Madison Avenue’s most powerful and influential media buying executives, will retire at the end of the year, extending the parade of veterans leaving the business at a time of extreme flux.

Cohen, executive director of media investments at WPP’s powerful GroupM, helped weave Sears into ABC’s “Extreme Makeover: Home Edition,” one of TV’s most memorable product placements; worked American Express into a lead sponsorship for Disney’s recently launched ESPN + streaming service; and was the executive who struck a deal with NBCUniversal in 2007 that created a new yardstick- known as “C3” or “commercial ratings – for measuring the effectiveness of TV advertising. Now she has decided to tackle other pursuits, such as writing books for children.

“There comes a point in your career when you sort of know it’s time, and you have to trust and be inspired by new beginnings,” Cohen told Variety in an interview.

She departs at a time when many of the media industry’s top negotiators are testing new fields. In recent years, big ad-sales chiefs like Joe Abruzzese and Toby Byrne have left places like Discovery and Fox Networks Group, for example. Ed Ehrardt, the top ad-sales executive at ESPN, is retiring. They leave as the move of video to digital transmission via broadband opens the industry up to ad deals governed more by algorithms and data than they are by handshakes and long-term relationships.

“She really made negotiating an art,” says Rino Scanzoni, CEO of WPP’s Midas Exchange and its advanced TV unit, Modi Media, and the former chief investment officer of GroupM. “She was always very persuasive and very tenacious when she was pursuig her goal. When I was running the GroupM operations, I always put her in charge of the most difficult negotiations, and the reason for that was because she is always creative enough to find a solution, tenacious to keep at it until she gets the desired result and she always had a terrific relationship with the people that we had to negotiate with that could actually make the decision on the sales side. She’s a loss to the group, there’s no doubt about it.”

Cohen has been with GroupM since 2001, joining to oversee TV placement for Unilever, one of advertising’s biggest accounts. She has also been associated for years with American Express and the retailer TJX Companies,and in recent years has been the GroupM executive finalizing deals with NBCUniversal and WarnerMedia’s Turner during TV’s annual “upfront” ad sales market.

Cohen has worked both sides of the table. Her resume includes stints doing ad buying and media planning for Lintas and Saatchi & Saatchi, but also working sales and marketing for places such as ABC, CNBC and UPN.

She helped forge some of TV advertising’s most memorable moments along the way. While working for General Motors Mediaworks, a buying agency devoted to the large automaker, she helped link the company to CBS’ “Survivor.” At GroupM, she was involved in arranging for Unilever to sponsor a global launch for the Fox TV program “Touch” (with Ellen Ferrari, now a prominent marketing executive at Samsung) and worked to have American Express sponsor the ability for fans of Fox’s “New Girl” to buy products they would see in the show.

“That’s what really drove me,” says Cohen, “if you could come up with these ideas no one else can and then people try to replicate them.”

Cohen has an ability to finesse deals that makes her valuable, says Irwin Gotlieb, the former global chairman of GroupM and an executive credited with developing media buying and investment into a separate discipline in the ad industry. “What she’s uniquely competent at is doing deals with a velvet glove,” says Gotlieb. “Whenever we’ve been at our most difficult position, and brute force wasn’t going to do it for us or would damage the relationship beyond repair, Shari was the velvet glove who figured out how to get it done.”

Her long tenure on some of advertising’s big accounts served Cohen well and allowed her to do more than just hammer media outlets on prices, says Jo Ann Ross, president and chief advertising revenue officer at CBS Corp. “She does get close to her clients, gets to know them ,and because of that closeness she was able to be very, very creative,” Ross says.
Cohen says she tried to spend time talking to programming executives as well as sales people in an effort to make her clients’ needs known. “A lot of my ideas came to fruition” she notes.

She says she takes pride in trying to be creative: “Great ideas, creativity – those are traits that can serve you well wherever you go.”