Temis, I don't understand your insistence on the stereotype that CBS caters only to really old people. [...] So nearly 60% of their audience is under 45, or at least it was five years ago.
This is true. However, haven't almost all studies shown that the median audience for CBS is older than that of any other major network? IIRC; CBS is in the 40s; ABC & NBC are in the 30s; and the CW, FOX, & MTV are all in the 20s.
CBS skews the oldest and it's been that way for a while. They make up for it on volume. But that strategy is doomed over the long haul.
Advertisers only care about 18-49. I thought everyone knew that by now. So skewing old becomes a real problem when the average age is starting to edge out of that demo.
Whether or not brand preferences are really locked in at 49 is a different issue. As long as advertisers think that way, they will continue to act on that belief, even if it is stupid and wrong.
I don't think much of the "targeted" advertising online, though. A couple of days ago I got a new landline phone at Staples -- and when I was browsing that evening, a Staples ad appeared on io9 offering to sell me the exact phone I'd just bought. How useless is that?
Or just look at this place, with that idiotic vertical banner in the wrong location! Somebody hit the wrong button.

Even the vaunted Netflix is screwing up. I get both streaming and DVDs. I didn't start getting House of Cards advertising on my envelopes until after I'd started watching that show. Shouldn't that have been the other way around?
The nice thing about online advertising is that it's easier to tell when somebody is messing up. If they know everything about us, there's no excuse for mis-targetted ads.