For membership organizations trying to figure out how best to support their members, choosing between seeking 501(c)(3) charity status and 501(c)(6) trade association status will usually involve weighing the benefits and disadvantages of the two different tax-exemptions.  

Not all membership organizations will be in a position to make the choice. The primary purpose of a 501(c)(3) charity must be charitable and educational, providing significant benefits to the general public. The primary purpose of a 501(c)(6) trade association is to improve a line of business activity of the members.