ccs
41st lv DM
Mike Mearls on Twitter, July 2015:
"@michael_natale it's tricky, because shorter adventures are hard to make work in book and game stores. we have some ideas, though."
I could have sworn there have been other mentions too, but I can't find them now.
And yet Paizo continues to do just that. Maybe Mearls should call them up & ask 'em how they do it.