Probably not much. But they represent opposite ends of the coveted 18-49 age demographic most desired by marketers. When it comes to major advertising campaigns, the 18-49 demo rules the roost, but does this traditional demo still deserve its status as the most coveted?

Advertisers know where to find the 50+ audience. They spend 5-6 hours a day watching TV, and compared to the under 50 crowd, they consume more radio and newspaper. For mass media advertisers, people over 50 are easy to find. But given the fragmented media choices in today’s landscape, those elusive 18-49 year olds are more challenging to reach. And for that reason, big marketers spend a lot of money and effort chasing them.

But does the 18-49 demo even matter anymore?

There are fewer 18-49 year olds today. Only 55% of all adults fit the demo (down from 62% a decade ago). Increasingly, 18-24 year olds live with their parents, and according to a study by Wilkofsky/Gruen Associates, 56% of 25-34 year olds now live in someone else’s home. “The biggest chunk of them are living with their parents” according to Wilkofsky/Gruen President, Arthur Gruen.

So why is 18-49 still the currency of the masses?

History has a lot to do with it. Baby Boomers were the largest group of consumers in history when they were 18-49. Also, many advertisers feel that younger people are more likely to be attracted to a brand as new customers, or to build an identity with a brand before becoming consumers.

For decades, 50+ age consumers were shunned by advertisers who deemed them less wealthy, less likely to try new products, and less willing to change brands. But as the country ages, the 50+ market is changing with it. And they are becoming the success factor for many advertisers., which markets children’s learning toys online, is the perfect example. They targeted parents of young families in their 20s and 30s, but found that nearly half their business came from older consumers, mostly grandparents. Or take the case of the Kia Soul, which was marketed to twentysomethings with dancing hamsters and Lady Gaga, but the average age of a Soul buyer is 48. Baby Boomers are all over 50 now. And they represent 59.7% of all beer purchases, 58.9% of all carbonated beverages and 54.2% of candy. All products traditionally considered to be youth-oriented.

Households led by 55-64 year olds have the highest net worth of any age group. From 1999 to 2009, the median family income for those 55-64 rose by 12%. The only age group close to that is 65-74 year olds whose income rose by 11% (The Grandparent Economy, 2009).

Insight Express released a study in which over a thousand media professionals were asked to value the most important demographics to reach. Not surprisingly, the 25-54 age group was the most important to media buyers, however, the 35-64 demo and 18-34 demos were judged to be equally desirable.

So, are 18-49 consumers even worth the effort? Absolutely – every consumer counts. But Lifestyle and Economic Demographics are more finely tuned ways to analyze media audience than age or ethnicity or gender.