New Brevoort Formspring

It’s really just a gut sense based on overall popularity and ability to sell comics, the specific status quo that the character happens to be in right at that moment, and the desirability of the story that another creative team wants to tell with that same character. It’s probably easier to do with a hero than a villain, in that we’ve at this point been conditioned for so many years to accept Spider-man being in two or more titles at once. Whereas Mister Sinister having two separate take-over-the-world-harvest-the-mutants-for-parts plans going on at the same time feels more difficult to accept. Even then, though, it depends on teh villain–easier to buy with, say, the Rhino, as the average Rhino situation tends to be more akin to a smash-and-grab than a master plan.