NiTessine
Explorer
I generally disagree.
Settings will mostly be used by those not creating their own. Of those groups they will be of most interest to the GM rather than players.
So you are talking about a fraction of a fraction of your player base interested in buying your product.
Its probably worth pointing out that it wasn't a strategy which worked very well for TSR.
No, the strategy that did not work out well for TSR was publishing five setting lines at the same time that were effectively competing with each other.
Paizo has one setting.
As for a major selling point... the key here is that it's a good setting.
Personally, I prefer Paizo's setting model to what WotC is doing with 4E, without even going to the issue of quality. Paizo produces a wealth of setting information but does not go into the deep detail level except in adventure modules that require it, leaving the DM room to tell his own stories in the setting.
As far as I can tell, there's also no metaplot.