Lotta good questions above, let’s see if I can answer some of 'em:
Q: What about topical/current events strips? how far do they work ahead?
A: Actually they work six weeks ahead just like any other strip. However, they can get special dispensation from their syndicate to insert special topical strips if the situation warrants it. If Trudeau, say, wants to insert a week of dailies about the fall of Baghdad right after the fact then his regularly scheduled strips on file get pushed back. Trudeau, in particular, does this inserting often, as does Magruder with his Boondocks strip. The syndicates consider the timeliness of their strips to be a selling point, and so these guys pretty much have carte blanche. Other strip creators are on a much shorter leash, but they do have the same privilege as long as the syndicate okays it.
Except in really rare cases special topical material cannot be inserted the day after the event. Newspapers receive their comics in weekly batches, and so special material cannot be inserted, at best, until the Monday after the event, without special cooperation from the newspaper. Sunday strips almost never use current event material because they have a longer lead time for production.
BTW, unlike strip cartoonists most editorial cartoonists work on a day-to-day schedule.
Q: How do cartoonists avoid repeating their ideas?
A: Um, just between you and me, they don’t. At least let’s say they don’t go tremendously out of their way to avoid the situation. I don’t know of any cartoonist, for instance, who keeps a database of used gags in order never to duplicate. On the other hand, most cartoonists do keep a file of gags so that they can be ‘switched’. Switching is an industry term for taking an existing gag and making enough modification to it that you can’t really be accused of cheating. The classic switch is to reverse the roles of your two characters and modify (slightly) the gag to accommodate the reversed roles.
Q: Does the cartoonist get paid for reruns?
A: The cartoonist gets a percentage of the revenues generated by the syndication of the strip. Thus, since the newspapers pay (with an occasional grumble) the regular rate for rerun material the cartoonist gets their customary cut. BTW, the industry standard is 50% of the revenue to the syndicate, 50% to the cartoonist. Yes, successful cartoonists do get FILTHY rich.
Q: What is your cite for this stuff. Are you a syndicated cartoonist?
A: No, but I am a researcher who specializes, believe it or not, in syndicated comic strips. I write articles about comic strips for various magazines. And no, you can’t make a living doing that (well, at least I can’t). I have a ‘real’ job too.