You’ve no doubt heard the tagline more times than you can remember, and chances are it’s felt fresh every time. What is it about MasterCard’s ubiquitous “Priceless” campaign that resonates not just with consumers but also with the three MasterCard CMOs who have reigned during the initiative? And what has enabled the messaging to maintain a freshness and consumer appeal after nearly 17 years? Can anything live up to “Priceless” in terms of longevity and universality? It’s not just 17 years, but 50 languages and 102 countries, too.

First and foremost, “Priceless” is about creating emotional moments, and the campaign has done this by tapping into something simple: people don’t have the time or the financial means to create those truly spectacular moments.

Or do they?

Not only did the campaign bring cherished moments to the foreground, it positioned these moments as both universal and highly accessible by alleviating any postpurchase guilt. The tickets to a baseball game, hot dogs, and autographed baseball are the investment—and after the money’s spent, the payoff is the real conversation with your son.

Another trophy in the case? Sure. But more importantly, it was truly the first—and one of the most innovative—viral campaigns in history. The “Priceless” campaign launched in 1997, long before the age of social media, but people still knew about dad and son and the autographed baseball. It was a big idea that resonated and socialized the old-fashioned way, without the crutch of now-universal viral tactics to give it wings. When “Priceless” started, MasterCard couldn’t really gauge its successes the way we can today. There was no definitive assessment to say “they say this campaign and this many consumers went on to apply for a card.” Today we have those tools and countless others. We can dive into the metrics for this and any other print, digital, broadcast, social, or mobile campaign and figure out ways for it to run farther and faster.

As social media ramped up so, too, did MasterCard’s envelope pushing. In 2011, the company took seats from the old Yankee Stadium, affixed QR codes, and stuck them near legendary New York City spots, driving consumers to check in on Facebook Places, back when both technologies were relative newcomers. As part of the same “Priceless Cities” initiative, MasterCard curated a series of truly exclusive events (think rehearsing with the Rock of Ages cast), helping cardholders create those in-ad experiences in their own lives.

The marketing campaign continues through 2013 and, no doubt, will forge ahead in 2014 and beyond. MasterCard, as well as any other integrated brand, is in a unique position at the intersection of measuring success and pushing even harder against those metrics to achieve something truly great and long lasting. MasterCard could even look to break its campaign into smaller, equally powerful calls to action to further hit on specific goals of the organization and enable the core campaign to live on in new, unique formats.

It’s a powerful thing to think about: longevity and constantly re-evaluating and re-imagining success. MasterCard has done it in a seemingly flawless format for close to two decades. Think about how you’re putting together your brand assets now and in the year ahead. Are they working as hard as they possibly can for you? Are you measuring your successes, and pushing even harder against those success metrics? What are your campaign goals, today and tomorrow? Mapping out long-term strategies and constantly re-imagining and re-assessing are critical—even “priceless,” perhaps.