I've been reading comics for 40 years or so, sometimes reading almost everything that comes out (mid-late '80's), buying when I had a few pennies (late '70's), getting sucked into storylines (most completely with Mavel's "Civil War") and skimming whenever I get the chance (now).
I do have an advantage to keep in touch as I now have a son interested in comics, though more for the movies and action figures, but enough to have conversations and re-kindle interest.
I've also read a lot of the history of comics - the origins of Superman during the depression, Marvel's beginning in the '60's, the "stealing" of Batman by Bob Kane, the public force of Stan Lee alienating co-creators Jack Kirby and Steve Ditko. I've grown to appreciate the form and the business of comics.
Continuity is one of the issues that is difficult to handle well.
Continuity:
The issue:
Do you create a "universe" where the characters retain a history of what has gone before, and a consistency between titles (e.g. do characters inhabit the same "space")?
Comics haven't always been around - newspaper strips were the early version, and comics started as re-prints in the late 30's. Some filler material was commissioned, all at the complete creative ownership of the publisher, and characters appeared and disappeared. Each month was typically a stand-alone, even if the particular characters re-appeared - little, if any, reference was made to prior appearances, and any referred to "history" was created on the fly ("ahhhh, Professor T, my old nemesis...) even if you have never seen Professor T before.
Superman changed things, and proved that monthly adventures staring a continuing character could work, and he saw spectacular sales, and imitators. Reading the early years, you see that Superman's character was revised without comment (e.g. moving from big jumps, like the Hulk, to flying), powers were added, strength increased to ridiculous levels - all without any particular reference to changes (nowadays, he'd be exposed to long durations of solar radiation or something to explain power fluctuations or new powers - some attempt would be make to explain why "this" Superman can do X, while last month's Superman couldn't). This was a reflection of the evolving medium, and the primary goal (which remains unchanged) was to increase sales. Siegel and Shuster would never have understood the durability of their hero, or the magnitude of the $$$ generated (this was the reason for periodic lawsuits and guilt trips to DC to pay the often impoverished creators of Superman out of the billions accumulated).
Monthly conics retained a consistency of characters, but were pretty loose with history, and relatively immune to expectations of continuity. They could interact with other heroes, or they could pretty much be the only hero on Earth, and could do so interchangably month to month, one writer could extend the power scope, the next could shrink it back.
Marvel, with Stan Lee at the helm, jumped on the resurgence of super-heroes in the very late '50's and early '60's, after the genre pretty much died at the end of WWII. DC re-launched a Flash and Green Lantern (similar to but updated from the 40's versions) which were successful. Marvel launched Fantastic Four and Spider-Man, both of which concentrated on a different model. Stan Lee tried to include the reader in the story (e.g. inside jokes regarding secret identity issues, clubs, talking directly to fans on text pages in the comics and footnotes, soapbox discussions, letterpage interatciton...). The footnotes were probably the smallest invention with the largest impact - these were used to point back to when the last appearance of a character was, or when a "hint" was provided in an earlier frame or issue, or pointing to an entirely different title - "Did you see the Beetle in FF#X" in a Spider-Man comic.
The long term impact of the footnotes was to create a cohesion between titles in Marvel, and a history that had "weight" - you could use earlier issues as reference sources - go back an re-read an issue with a new focus ("I didn't know that guy was the Green Goblin - look he's dropping Peter and Harry off at school - cool!"). This interest was reinforced and magnified through Stan's use of "no-prizes" a reward on the letter page for fans who pointed out inconsistencies and resolved them in a manner consistent with this new universe (e.g. you'd get credit for identifying a flaw - "Hey, why didn't the Human Torch just fly out of the box?" - but could get a no-prize for resolving it - "I guess the Invisible Girl had an invisible shield over the box to protect her brother").
This interaction made the Marvel comics popular, and from a marketing perspective, was an excellent way to "encourage" readers to try other comics ("see Johnny and Ben in Strange Tales and be back next month for FF #X" or 'Doctor Doom (a Fantastic Four villain) pesters Spider-Man next month, don't miss it").
Why is this a problem?
Well, in general, it is not. Creating a cohesive universe has distinct advantages - you don't have to explain the premises all the time - fans learn what is "OK" and what it "a violation" of the rules, if you keep them consistent (e.g. Spider-Man has physical powers, he can't do magic, Superman can fly, but Batman can't). Typically, aside from the powers of heroes and villains, pretty much everything else is "normal" - people have jobs, the stories are set in the real world (Metropolis and Gotham for New York in DC, New York itself in the more 'realistic' realm Marvel created in the '60's).
The unanticipated problem comes about when the characters are 50 years old (Spider-Man and Fantastic Four, or 80 years old - Superman and Batman). The history is long and intricate (though you can probably ignore the first 30 years or so in DC, as continuity was not an issue then) so the writers of comics were often hemmed in as to what storylines they could build. They needed to have a full understanding of the history, last appearances, powers, origins, etc. of thousands of issues and characters or they faced the "wrath" of the long-time readers.
I mentioned earlier that the characters were wholly owned by the publishers - this wasn't a big issue when you didn't know if you story would carry on for 2 months, but became a gigantic issue when the comic you wrote/illustrated is now worth $1 million, and your original artwork sells at auction for $50,000 per page. There was unknown gold in those pages, and the creators were not being compensated for any of it.
Many lawsuits and secret deals were created, but moreover, the new crop of talent was made aware that their midnight scribbles, or the character they've been thinking about for 10 years could become valuable, but they could be removed from it entirely (both creatively and financially) due to the whims of the industry. They got smarter and started to market themselves and their characters.
Thus, the "new age" created stars of the artists, and led to conflicts with the "old school' publishers, who retained control of the characters. Thus, what do you do when an artist such as Todd McFarlane works very successfully on Spider-Man, but wants to do things with the character that are not in line with 30 years (then) of history? The publishers try to reign in the artist, give him a standalone title, but eventually the grass of a creator-owned character (and publishing house) becomes too strong and the more independent of the popular artists leave. They can create their own characters, unburdened by editorial oversight and not having to adhere to a long history (sometimes poorly thought out, or inconsistent history) that is sacrosanct in the main industry.
The era of complete control by the publisher is probably gone for good. They haven't relinquished control over their key characters (that is the value of the publishers, so they won't, and shouldn't relinquish control), but the interaction is more negotiation than fiat. Creators run between different publishers, and it is not uncommon to have mainstream titles with particular artists and writers on the shelves for one publisher, and fully creator-owned titles on the same shelves by the same individual for a different company.
How to handle continuity?
Here is where there is debate. One mechanism, started by DC in the mid-80's for Superman, is to basically re-launch characters (or whole universes) to re-set the history. You can completely start over (like John Byrne's Man of Steel series which re-launched Superman) where you have an updated origin, and you re-create from scratch, pulling in characters from the "old" version if you like, giving them updated origins themselves, and having "1st encounter" stories in the new reality. You could also re-start (like "Crisis on Infinite Earths") where you acknowledge that there have been many "histories' of characters, and simplify into a new reality, with some aspects and characters pulled forward, some ignored, some updated - in this method, you can still claim the character is continuing (e.g. Superman has been around, we're keeping the '30's origin story, but ignoring his "super telepathy", "kyrpto", boyhood as Superboy etc.). This second method is actually just an updated version of what occurred in the past, just more completely acknowledged (you'd have had pieces of history you ignored, you'd have history you'd hold dear, you'd modernize the character over time) but in this method, you try to explain the new reality in a universe-related manner.
The problem with re-boots, is that in a continuity mindset, there is a feeling that the older stories "don't count" or are now devalued. If these are the stories you grew up on, it would be like they "fooled' you into liking the character.
The advantage of re-boots is that it is honest, and a reflection of what needs to be done - you can structure the re-boot to take advantage of existing history or re-write it - you are up front with your change. This allows for a relatively painless start-over.
Any sort of revision is going to be met with some pushback from long term readers, particularly if they have an attachment to the character(s). However, the "pull the bandaid off" strategy at least minimizes the damage.
DC has done this re-boot in the "startover" method with Superman in '86 where they stopped publication of Action Comics and Superman for a period of time, launched a mini-series to re-origin and start the new Superman off, and then re-launched Action Comics and Superman with new #1 issues, and a third title, Adventures of Superman, which continued the older numbering from the first Superman series.
DC and Marvel have had changes to continuity (I doubt I've covered them all) through large events, starting with the Crisis on Infinite Earths, where DC amalgamated their different realities into a new one - not as clean as the re-boot, but a substantial change in status quo which gave the creators some freedom, and cleaned up the history of the longer-term characters.
Marvel has made fun of the DC reboots, and through their fanbase, implied that it was a function of long term bad storytelling (maybe to some degree, but more a function of much longer history than ever anticipated, and pre-dating the more modern age). They have tried to make major character changes, WITHOUT acknowledgement or re-boot processes, and, in my humble opinion, have done a lot of damage to their characters and their "universe".
Spider-Man is probably the iconic image of Marvel, along with the Fantastic Four, launched the current Marvel Universe. This character was a nerdy loner in the early stages, worrying about money and having little success in either identity, and everyman with an accidental transformation.
He has also been (much more recently) a most-recent version of a mystical spider-cult, member of the Avengers, assistant of billionaire Tony Stark, successful scientist/inventor... all of which are quite a departure from the original concept (not necessarily bad, just substantially different). He was also a married man with a supermodel wife (Mary Jane), which also put him at odds with his "loner/loser" history, and, to many higher-ups at Marvel, limited the storytelling and aged the character.
To revise this character, Marvel did not choose a re-boot, but had Peter Parker make a deal with Mephisto (the devil in the Marvel Universe) to save the life of his aged aunt who was shot by a sniper aiming at Peter. For much of the fanbase, this was a departure of a huge magnitude from the straightforward character Peter was always seen to be - honest, reality-based (e.g. non mystical) - not someone who would deal with the devil. To make matters worse (in the same eyes), Marvel did not use this significant event to remove any of the problematic storylines which affected the character (e.g. the idea that the clone of spider-man was the real one, not the one followed for many years in the comics, the spider-totem mysticism that removed Peter from the "normal guy" into a chosen one, and the retroactive story that had a sexual relationship between Peter's most significant girlfriend and the Green Goblin which resulted in children...). In fact, Marvel seemed to be trying to distance themselves from their long-term fanbase by not only not making changes that this fanbase expected, but by driectly antagonizing that same fanbase directly. Whether or not this strategy is effective remains to be seen.
What are the ramifications?
Comics since the early '60s (and to a large degree since the late '30's) have been a sequential story telling medium. Marvel built their base on a common universe with a consistent history and interaction among characters.
Both Marvel and DC have become heavy with history.
What can be done? Re-boot (DC model) where you re-start periodically to clean up and simplify accumulated history. Pros - simple, straightforward; Cons - runs the risk of "orphaning" storylines or points in history and having a snowball effect on the consistency of the characters. Too frequent re-boots, too little character consistency, too few re-boots, too much accumulated history to account for.
Re-jig (Marvel model) where you consider all the history to be "real" but do major re-shuffling without clear deliniation or clarification (e.g. Brand New Day). Has the effect of re-setting history, doesn't require all answers to be created at start which allows for flexibility, but tends to alienate hard-core fans and does not clear up the history and characterization as clearly as a re-boot, but also is not necessarily as disruptive as a full re-boot.
A third method is to "abolish" continity beyond a particular creative team or duration of a title. For example, treat Hickman's Fantastic Four as a complete storyline - consistent within the storyline, using established characters, but not definitive going forward (e.g. later creators can also start with the characters, not tied to the history or stories Hickman created). This is what I call the "Tarzan Method", as the Tarzan character has been around for a long time, has some consistent properties, but is really a relatively blank slate for a series - you can start with the basic framework, and aren't tied to an existing history.
This 3rd model is kinda' been adopted when the graphic novel serialization of comics became more popular - creating a series of 5 or 6 issue storyline creates a nice package to bind into a book and sell in non-traditional comic markets (online, bookstores, libraries). These compendiums also provide a way for a novice reader to get a complete story in one volume (there is speculation that the comics world became too complex, and only a fanboy could follow the stories - new readers took time to understand what was going on as there were so many references and cross-references).
I must say that I really don't like the Marvel re-jigging - I understand they were trapped by their statements regarding only weak storytellers requiring a re-boot, but they really seemed to mix all the "bad" together without getting a clean universe going forward. I have no interest in the Brand New Day Spider-man (the deal with the devil and the Gwen Stacy smearing are the primary reasons, the mystical totem is also a problem) - I have always liked the character, but it needs to clean up some of that awful history. It is not the damage to the fictional Spider-Man that is the issue as much as the disdain that Marvel seems to have about the consistency of their own characters. The only "value" Spider-Man has is the accumulated consistency and the good will of the fanbase.
I'm sure that eventually I'll climb back aboard, but I think there is a real difference between the pre-Mephisto character and the post, with respect to how much attachment is reasonable to the character - if Marvel is willing to throw out years of continuity, and is not interested in the core values of the character as created, it is much more difficult for me, as a fan, to care very much. This, however, may be the marketing strategy to free up the character (without protest) to be flexible enough for movies, TV, video games, etc. without being tied to any particular "version".
The re-boots I am willing to accept as a necessary evil, though the companies should know there is damage sustained with each blow. However, if the re-boots are far enough spaced in history, the "blows" should not be cumulative, so they will be weatherable. If they are "too frequent", re-boots have the same flaws as the re-jigging. What is "too frequent"? Who knows, I'd expect 15-25 year windows to be "reasonable" as you may be into a different cohort of readers when the subsequent re-boot occurs.
My fear is that the creators are not valuing the creations enough, and that the sequential storytelling will be lost to the higher profit movies etc. I think they need to keep the less profitable avenue of comics alive, or there won't be the sustained interest in the characters to make the movies popular, and there won't be the creative room to explore the character properly to make the movie storylines. Once the "sequential" part (e.g. monthly comics) is removed, all characters revert to Tarzan - shells to be played with, but not rich histories to draw from - the end of the world? Probably not, but likely the end of some characters as the baseline interest in them wanes.
I think there may be a compromise solution - a soft-continuity, where, perhaps, the last 5-10 years or so are considered canon, but older storylines can be ignored, altered or re-used to keep the characters fresh. This keeps the "history" of the character consistent (can't drive off a cliff if you are keeping the last 5 years in memory), without having to carry around an omnibus of knowledge to write a story. The "moving history" also allows for evolution of characters, without the sudden jumps and bounces of re-jiggs and re-boots.