Very. Between it and the baernaloth stories I'd posted up on Planewalker and elsewhere, it helped me get my name out there. When I first submitted some queries to Dragon, one of the editors knew me right off the bat from those stories. And prior to that, they'd incorporated an idea from a storyhour excerpt that I'd posted into a plot hook in a planescape campaign classics article in dragon (the one that rumored about Factol Nilesia being flayed by the Lady of Pain)*. Any way of getting your name and your work out there in public is a good thing towards getting industry folks to notice you. I hesitate to call it that, but shameless self promotion will get you places.
While that first particular query never made it to print -a big piece on baernaloths- the next few queries did. And it was the various things in Dragon and Dungeon I had that I think got me in the door for work with the guys at Paizo now with Pathfinder.
*and it's honestly unfortunate they went with that instance from the storyhour, because well... it wasn't so black and white of a thing, Nilesia being flayed to death in public. We aren't there yet, but her story is by no means over in this storyhour.