Are we talking about manufactured brown sugar or natural brown sugar (raw sugar that has not been refined)?
I could see using either, as the brown sugar you buy in the stores is refined white sugar that has had sugar cane molasses added to it. Raw sugar is sugar that has not been refined into white (table) sugar. The molasses has not been spun off from the sugar crystals in the refinind process.
I've seen both brown sugar and raw sugar offered as sweeteners at some coffeeshops. You see the raw sugar (Best known brand is "Sugar In The Raw", which comes in light brown packets) more often than you do the manufactured brown sugar.