Well, my campaign is a bunch of unrelated adventures. There is no overarching story arc, but there are events that carry on that the PCs can get involved in.
I also drop in hooks for several adventures in each adventure I run, and the PCs chase the hooks that interest them. In my current adventure, Goodman Games' "People of the Pit", the PCs have found a map in a strange language. The sage knows hte city he can get information and translation from. If they follow up on this, it'll lead to "Dwellers of the Forbidden City", which I'm "mashing up" with the old Goodman Games' "Emerald Cobra" and POSSIBLY "The Hidden Shrine of Tamoanchan".
In that mix of adventures, there will be a hook to "Chadranthar's Bane" from Dungeon Magazine.
Of course, the party could go another way. One of the PCs is a Lycanthrope (and no one knows! How often does THAT happen?), and if she wants to get cured, I have to figure out a story arc to run for her.