Even without invoking a certain currently-on-hiatus show that romanticizes the glory days of ad agencies, you might have noticed that the catchphrase, while not quite extinct, has lost much of its resonance in recent years.
This is especially the case for the humorous one-liner wedged into the middle of a TV spot, as opposed to the more self-serious tagline, like “Just do it.” Rather, the most popular ads these days star recurring characters who tend to eschew idiosyncratic utterances. Even one of the best-known spokesmen around, Dos Equis’s “The Most Interesting Man in the World,” is probably less recognized for his kicker — “Stay thirsty, my friends” — than for the conceptual joke behind his persona.
On the other hand, it seems like "What day is it today? It's hump day" is pretty close to achieving catchphrase status.
