Off the top of my head the first thing that comes to mind is "A forum for marketing nonprofits"? sounds a bit boreing so I'm not sure how many people would come by to post about the subject. A blog on the other hand will #1 give you the opportunity to talk about your vision #2 allow others to read and analize your concepts and directions.

Forums (like this one) IMO attract people who often have no interest in the overall direction or spirit and intent of the forum. They just come by for bits and pieces and don't really contribute. Of course this is just an off the top of the head opinion. I'm sure you will get better info from others.

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"What you hear in a great jazz band is the sound of democracy. “The jazz band works best when participation is shaped by intelligent communication.”
Harmony happens whenever different parts get to form a whole by means of congruity, concord, symetry, consistency, conformity, correspondence, agreement, accord, unity, consonance…….