Lauras right.
AC publisher is a nice function I believe.
If you use the Shortcut button on the bottom
left of attached screen shot you don't have to
keep updating your publisher set.
Verses if you had dragged over the layouts.
Of course after you have published layouts to say, a folder,
and you change something on layout, you will have to
republish, but you would have to do that anyway!
But you don't have to drag over the layouts again and make
new publisher set, it's done automatically.