After years of chasing the 18-to-49 demographic, TV may be shifting its target audience as the American population ages.

The median age of a broadcast television viewer is now the highest ever at 54. Twenty years ago, it was 41. The most-watched scripted series in the 1993-94 season was “Home Improvement,” with a median viewer age of 34. Today, it’s “NCIS,” with a median viewer who is 61.

Confronted with these realities, the networks are aggressively making the case to advertisers that older viewers are valuable — especially the affluent and influential 55-to-64-year-olds they’re calling “alpha boomers.” The 50-and-up crowd of today, they contend, is far different than the frugal and brand-loyal group that came of age during the Great Depression and World War II…

Younger adults, busy with school, careers, socializing and child-rearing, have always watched less TV. Now they’re even harder to find, thanks to technology that allows them to watch TV whenever and wherever they want, and to skip over commercials…

A decade ago, networks primarily sold ad inventory for prime-time shows based on how many 18-to-49-year-olds were watching at home. Now, network sales teams are emphasizing other metrics, such as income and education level of viewers.

The population bulge known as the baby boomers continue to influence American society. There was a really nice infographic in the Chicago Tribune version of this story (I can’t seem to find it online) that clearly shows some of the patterns across networks: CBS has the highest median age where even their “younger shows,” like How I Met Your Mother and 2 Broke Girls, have a median viewer around 50. The youngest network, by far, is Fox with six shows with a median age under 40 whereas no other network has 1 show under 40 and each only have a few under 50.

It would be interesting to then compare these shifts on television to other areas of advertising and marketing. Can advertisers move away from targeting young people on television because it is so much more effective to target them on social media and websites? Or is television still such a big deal even with declining numbers that Internet advertising still can’t compare?