In 1977, a famous episode of the popular TV show Happy Days depicted Henry Winkler's character, "Fonzie," jumping over a shark in water skis. For a series that had gotten its start depicting events most adults at the time would remember about their youth in the 1950s, this was a rather severe departure. The stunt was viewed by the show's critics as a shameless attempt to "goose" the ratings, and many people mark that event as the "decline" of Happy Days.
Now, to be fair, Happy Days was a successful enough show that it ran for another seven seasons. But its ratings slowly declined year after year following this event, and many of the original fans felt that the show had lost something. The shark-jumping episode is seen as an "inflection point" in the show, with higher quality, more "true to form" episodes before it, and increasingly hype-oriented, gimmicky shows following it.
Since that time, many TV shows have followed a similar pattern. They start out with a certain thematic emphasis, and the show remains good or even improves each year for several seasons. But then, something happens. Maybe the writers run out of ideas. The episodes become flat, stale. Perhaps people feel they have seen it all before. Ratings begin to decline, and that means the show is not making as much money (from advertisements). The show's producers need to do something to get people to watch. So they start resorting to gimmickry in the hope that people will tune in to see this new change for the show. Common changes to TV shows include events like having a new baby, or pretending (and not ironically) whole entire seasons have been "just a dream."
This descent into gimmickry in the desperate attempt to keep viewers tuning in has been named after that famous Happy Days episode. Whenever a show starts churning out episodes with the express purpose of "getting people to watch," rather than just putting out quality stories, people say it has "jumped the shark."
What does this have to do with +DC Comics and +Marvel Entertainment? Well... everything.
Recently, for example, DC announced "Supervillain Month." This will be a month where every single title in their line will star the hero's arch-enemy instead of the hero. Additionally, each comic will sport a "3D effect" cover. As I read the announcement for this "event," I could only shake my head. They're not even trying to cover up the fact that this is pure and utter gimmickry at this point. This event is pure hype -- a bare-knuckled attempt to goose their badly slumping sales figures. Rather than instructing writers to just write really great stories, DC is making its creative teams put out contrived one-shot stories whose only purpose is to sell comics. This is the very essence of shark jumping.
And let us not pretend that Marvel is any better. They have multiple "events" going on over there right now, including one that spans the mutant books, and the "Age of Ultron" crossover. Books that are participating in Age of Ultron have an "AU" after their number (e.g., issue "14 AU") to try and induce readers to buy them for the "crossover content." Here again, we have the companies attempting to attract readers using gimmicks, rather than just telling quality stories and figuring that quality will sell itself.
And let us not forget both companies' recent penchant for canceling and renumbering series back on issue 1 at the drop of a hat. Everyone knows issue 1 sells the best for any series, because thousands of people will pick up a first issue "just to try it." They may not buy any more, but #1 will get them to sample, and some will stay, and even if no one does, that first issue will make the companies a lot of money just because of its number. This is yet another contrivance, designed to induce sales because of a numeral printed in the upper or lower corner of the cover, regardless of what is on the inside.
In the meantime, what is actually on the inside is, in many cases, unreadable sewage. Take the Superman Family's H'el on Earth crossover, for example. Once again, the crossover is pure gimmickry. The villain (H'el) is utterly contrived and given whatever powers they need him to have so that the entire Justice League plus Superboy and Supergirl can't defeat him. The trajectory of stories in the Superman Family of books was utterly ignored by the writers. The story-line was, in a word, awful. DC seems to have figured that people will buy any issue with a gimmick in it -- again, this is what is meant by the term "jumping the shark."
What can be done about this? Well, that's hard to say. Although many TV shows have limped along for years after jumping the shark, I don't think I've ever known one to recover once the tailspin has begun. Instead, typically, the show continues to spiral downward, getting worse and worse over time, until one can't bear to watch it any longer. These shows tend to peter out, with ratings in the toilet during their final season, and everyone sighing with relief when the network finally pulls the plug.
The only other real option seems to be "going out on top." The cast and crew, writers and producers, realize that the show has run its course, that they are out of ideas, and they just stop. The shows that do this tend not to last as long as the ones that jump the shark, but they also tend to be remembered as the greatest series in television. Examples include the Mary Tyler Moore show (which ended after 7 seasons), the Dick Van Dyke Show (which ended after 5 seasons and coincidentally co-starred Mary Tyler Moore), and Star Trek: The Next Generation (which ended after 7 seasons). Each of these series produced some of their best work during the final season or two, and each was purposely ended while things were still good, explicitly because the creators did not want to have the show wither and die, to outlive its popularity.
And perhaps that's the real problem. To keep publishing series long after they have outlived their popularity, there's really no option but to use gimmick after gimmick. I would argue, however, that if the comics companies have been reduced to such contrivances, it's better to just put the series out of their misery, and let the creative teams replace them with something new, and different, and hopefully fresh and interesting. I guess what I'm saying here is that I'd rather see them cancel Superman, than keep resorting to hype-oriented gimmicks to keep it afloat.
Either way, I think there isn't any argument about one thing: DC and Marvel have jumped the shark with nearly every series they currently publish.