The dairy industry may be retiring its iconic "Got Milk?" ad campaign, but that doesn't mean you can't still learn a thing or two from one of the most enduring ad campaigns of the last couple decades.

Launched in 1995 by the California Milk Processor board (and later adopted by the Milk Processor Education Program), the slogan and corresponding campaign accomplished the seemingly insurmountable task of making milk funny, even sexy, with legions of celebrities lining up to appear in its ubiquitous print ads. This week, AdAge reported that MilkPEP is finally exchanging the milk mustaches for a new $50 million campaign, based on the slogan Milk Life, sending a collective wave of nostalgia throughout the advertising industry.

To find out a bit more about why "Got Milk?" had the staying power it did, I spoke with San Diego State University marketing professor George Belch. Here are four takeaways for any marketer:

1. It was simple, and it stood for something.

The greatest taglines, Belch says, don't require consumers to do too much thinking, but they shouldn't be blanket statements, either. "Got Milk?" he says, is not only dead simple, but it motivates the consumer. "The message is: always have milk around," he says.

It sounds easy, but Belch warns, not all brands have succeeded in conveying such a unique and powerful message in just a few words. Take JCPenney's old tagline, "Every day matters." 

"Sure it does," Belch says, "but what does that have to do with JCPenney?"

Compare that to slogans like Home Depot's "You can do it, we can help" or BMW's "The ultimate driving machine," and it becomes clear that it is possible--and imperative--to develop a tagline that says something unique about your company.

Unfortunately for the dairy industry, Belch says, "Milk Life is a little general, and I think they're going to have to execute well to get people to identify with that slogan."

2. It was actionable.

The great thing about milk, Belch says, is you either run out of it or it goes bad. Either way, you'll need more, which means "Got Milk?" served not only as an advertisement, but also as a friendly reminder. 

"It's a question, and it has a motivational element to it," Belch says, adding that the original directive for the ad agency, Gotby, Silverstein & Partners, was to drive sales, not general awareness. 

"They knew that to make this thing work they had to do something that was really focused on changing people's behavior," Belch says. Hence, the motivation implicit in the slogan.

Before launching an ad campaign, Belch recommends, be sure to have a clearly defined end result in mind, and design the campaign around achieving that one goal.

3. It used humor.

Who could forget the famous "Who shot Alexander Hamilton?" commercial that started the whole thing off? It centered around an Alexander Hamilton afficianado couldn't enunciate the answer to a radio show quiz question because his was mouth full of peanut butter, and he had no milk to cleanse his palette. Perhaps a bit corny today, but in the 90s, it was a hit. 

From then on, Belch says, the campaign continued to find a way to make milk funny, which as countless Super Bowl ads have shown, is one of the most effective advertising tools there is.

4. It was integrated.

Almost as important as what the ads said and how they said it was where the ads appeared. "Got Milk?" Belch says, handled different platforms from television to print to billboards expertly. 

"They were putting these billboards right around stores, and if you saw a billboard, it worked," Belch says. "They were really astute in their media planning."

Today's multimedia landscape, of course, makes that a greater challenge marketers. But Belch says it's still crucial to be mindful of where and when customers could come across your campaign and to differentiate it based on the platform. "We're moving into a new world of marketing communication," he says, "But you still need to hit all the consumer touch points."