Marvel's Agents of SHIELD, which premiered on Sept. 24 on Disney's (DIS 0.18%) ABC network, expanded the Marvel Universe -- united on movie screens by the Avengers franchise -- to the small screen. Although it's not the first time that a comic book franchise has been adapted into a TV show, it is the first time that a TV series occupies the same universe with the movies from which it was spun off of.

Agents of SHIELD is a direct continuation of The Avengers, taking place after the climactic Battle of New York. Although many of the show's characters are new, Agent Phil Coulson (Clark Gregg) -- who was assumed to have died in the film -- returns to life to lead SHIELD, accompanied by another familiar face -- Agent Maria Hill (Cobie Smulders).

Agents Coulson and Hill reunited in Marvel's Agents of SHIELD. Source: Wnypapers.com

Agents of SHIELD, penned by The Avengers writer and director Joss Whedon, lacks the expensive epic punch of its big-screen brother, but it exhibits a charming, intimate connection to the Marvel universe by relating directly to the events that have occurred in the other films. It also fleshes out Coulson as a funnier and more likable character than he was in the films.

Above all else, Agents of SHIELD does something very "comic-book like" -- not surprising since Whedon is also an established comic book writer -- it establishes a firm continuity for the Marvel Cinematic Universe.

The importance of creative continuity

It's that establishment of continuity that makes Agents of SHIELD such a game-changer for media companies like Disney, Time Warner (TWX), and Sony Pictures (SONY 1.10%).

Time Warner, for example, has struggled for many years to tie its core DC comic characters together in a cinematic universe. The modern movie Batman arrived in waves -- with two gothic Tim Burton films, a pair of campy Joel Schumacher films, and finally the more realistic Christopher Nolan trilogy, all existing in their own timelines.

Superman was also stuck in a similar cycle -- the classic Christopher Reeve films started out strong under director Richard Donner in 1978, but burned out with Superman IV in 1987. The franchise was then partially rebooted by Bryan Singer's Superman Returns in 2006, and finally completely rebooted by Zack Snyder in this year's Man of Steel.

When Batman pulls out a credit card (Batman & Robin, 1997), it might be time to reboot the whole franchise. Source: Wikia.com

However, Time Warner has apparently learned from these past missteps, and is bringing Superman and Batman together in its first true attempt to build a DC cinematic universe -- an upcoming film that will star Man of Steel's Henry Cavill as Superman and Ben Affleck as the new Batman.

Sony Pictures, which owns the movie rights to Spider-Man, also seems to be struggling with the future of the franchise. After Sam Raimi's three successful films, which carefully balanced humor, drama, and action, Sony decided to take a more serious turn with 2012's The Amazing Spider-Man, a complete reboot that attempted to follow Nolan's Batman example by making Peter Parker a more serious and gloomier character -- which felt far less epic than Raimi's 2002 Spider-Man.

DC's tradition of endless reboots

In many ways, these reboots mirror the comic book worlds on which they are based. Since Batman and Superman have appeared in comics continually for decades, their worlds have been rebooted countless times. DC Comics is notorious for this, using repeated reboots like Crisis on Infinite Earths (1986), Zero Hour (1994), and Infinite Crisis/52 (2006/2007) to combine all of its stories into a single coherent timeline.

Crisis on Infinite Earths, 1986. Source: Comicbookalliance.com

Marvel has authorized "soft reboots" in the past as well, but nothing near the epic nature of DC's world-colliding, universe-shattering sagas. For the most part, the Marvel Universe has remained persistent. It pulled heroes from the past, like Captain America, into the present, instead of replacing him with a modern version. It didn't feel the need to wipe out everything, generation upon generation, for the sake of clarity and freshness.

This is also a core strength of Marvel's modern movie universe -- which has flourished despite lacking core franchises like Spider-Man and the X-Men -- in comparison to DC. Whereas DC spent most of the past three decades creating self-contained cinematic sagas that eventually burned out, Marvel has spent the past five years carefully crafting a movie universe as seamless as its comic book one by signing all of its main actors and actresses to multi-film contracts. Although Robert Downey, Jr. might not always be Iron Man, the cinematic universe where his character resides could remain intact for years to come.

A big boost for Disney

With Agents of SHIELD, Marvel has now expanded that seamless universe into television as well. That strategy will benefit its parent company Disney, which has struggled to find ways to revive slumping ratings and advertising revenue at its ABC network, which has become increasingly associated with female-friendly programming like Desperate Housewives, Grey's Anatomy, Scandal, and Revenge.

Agents of SHIELD could give Disney the boost it needs with the coveted 18-49 demographic that has increasingly leaned toward AMC programs like The Walking Dead and Breaking Bad. In addition, it could help build audience anticipation for the next few Marvel films, enhancing ticket sales of films that are already considered guaranteed blockbusters.

Lessons for other companies

Other media companies can learn from Marvel's example. Companies generally use toys, games, and comic book adaptations to keep their films relevant and fresh. However, these are all temporary solutions that require marketing for each product. What Marvel has done harkens back to the days of classic Saturday morning cartoons like Transformers, Teenage Mutant Ninja Turtles, and Pokemon -- which have all been labeled as long toy commercials.

Agents of SHIELD is basically a 44-minute long commercial that returns every week to generate advertising revenue on its own. It's a brilliant tactic that could change how Time Warner, Sony, and Fox view the importance of the continuity between their film and television franchises.

Time Warner already has a DC comic book TV series, Arrow, which could be used as a starting point, and it will be interesting to see if it builds upon that series to better connect its movie and TV universes to follow in Marvel's footsteps.