Desdichado
Hero
I would have speculated the opposite; that good--or at least decent--splatbooks have a longer shelflife than adventures. If nothing else, the fact that adventures were migrated to third party sellers and magazines supports that notion. Ryan Dancey et al at the time were quite vocal in saying that the profit margin and shelf life of adventures was quite small--it was something WotC simply wasn't interested in because a company of their scale couldn't do effectively.I agree splat sells initially. however I question whether it is sustainable over the long haul. This is just speculation, but I think the reason WOTC keeps releasing new editions or half editions in such a short span is because the splats paint them into a corner eventually. Whereas if they took the approach Paizo seems to be taking I think they would have less of a big burst initially but more steady sales across the span of a single edition. Just speculation, and admittedly it is informed by my preference for non splat material.
Also, I don't think new editions and half editions have anything to do with splatbooks. Heck, back in the TSR days, there were more releases of new games bearing the D&D logo than during the WotC days. And the 3.5 edition was a bit of an aberration. If you haven't ever read it, you should check out this post on Grognardia, and then read Rick Marshall's comments in particular.
GROGNARDIA: Thank You, Ryan Dancey