Motion picture director Billy Wilder was once asked whether he would ever again hire Marilyn Monroe, who was routinely late to the set.

“I have an aunt who’s always on time,” Wilder answered, “but nobody would pay a nickel to see her.”

That tells you a lot about the business of acting. The ultimate judge of the work is the audience, not the employer.

This week, something interesting didn’t happen. The actors’ union —Screen Actors Guild-American Federation of Television and Radio Artists — did not go on strike.

Instead, SAG-AFTRA reached a tentative agreement with the advertising industry for a new three-year commercials contract.

“The success of this negotiation,” said the ad industry’s chief negotiator, Douglas Wood, “reflects the sense of partnership the JPC and SAG-AFTRA have built over the past fifteen years.”

What happened fifteen years ago? The JPC — Joint Policy Committee of the Association of National Advertisers (ANA) and the American Association of Advertising Agencies (AAAA) — tried to break one of SAG-AFTRA’s most lucrative contracts by changing how actors are paid for commercials on network television.

Maybe you would have bet that national advertisers — big, powerful companies — would easily win a fight against actors. You’d have lost that bet.

The commercials contract was born in 1953 after a three-month strike by the Screen Actors Guild. Under the agreement, actors would be paid a “session fee” for each commercial they made, and they’d also receive payments for use of the commercial based on the number and size of cities in which it aired, for as long as it aired.

At that time, TV networks led the bargaining on the management side because they sold entire programs to one sponsor. When TV advertising became more like magazine advertising, with different sponsors throughout a program, the lead role in bargaining fell to advertising agencies.

But high costs began to cause friction between the agencies and their clients. In 1976, an advertising expert named Arthur Bellaire published a book called “Controlling Your TV Commercial Costs.” Edward G. O’Neill, an executive with the nation’s biggest TV advertiser, Procter & Gamble, wrote the foreword for the book and made sure it was widely read by other advertisers. The chapter on talent payments was titled, “The Cost that Never Stops.”

By 1978, when negotiations began for the new SAG-AFTRA contract, the actors’ unions found themselves across the table from the newly created Joint Policy Committee of the ANA and AAAA. The chief negotiator for the JPC was a consultant from a Washington, D.C. law firm specializing in management-labor relations. His name was John A. McGuinn.

Screen Actors Guild’s chief negotiator, Chester L. (Chet) Migden, later said it looked like the beginning of a civil war.

Management’s first proposal would have put actors on a flat rate for an eight-hour day regardless of how many commercials were produced, an idea the unions immediately rejected. The JPC’s second proposal was effectively identical, calling for actors to perform in unlimited and undefined “alternate scenes” for a single session fee. The demand was non-negotiable. The strike began Dec. 19.

McGuinn led a nationwide effort to convince advertising agencies to produce non-union commercials in an attempt to break the strike. The JPC’s slogan was “Business as usual.”

But by the first week of February, the advertisers caved. Actors won significant wage hikes, and the “alternate scenes” proposal was watered down to nothing.

The actors prevailed because the non-union commercials were no good. The ads weren’t convincing anybody to pay a nickel for the product.

Acting is tougher than it looks, as are actors.

But the JPC and McGuinn didn’t give up. In 2000, they tried again to break the actors’ contract, demanding that the unions agree to replace the pay-per-use formula with a fixed fee. The actors went out on strike for six months, and despite McGuinn’s assurance that it was “business as usual” without them, the non-union commercials were still awful and the advertisers caved in again, gaining nothing.

John McGuinn retired.

That’s what happened 15 years ago.

Attorney Ira Shepard, who with McGuinn led the 2000 contract talks for the JPC, later told Advertising Age, “The current contract’s basis is in the 1950s, and if you try to change a contract that hasn’t been changed in many, many years, it’s going to be a very tough negotiation.”

But it’s not the age of the contract that makes the negotiation tough.

Actors should get more respect. It’s not that easy to talk somebody out of a nickel.