I read on SWGCraft.com that you get user xp up to the amount of xp you got for making the item. As an armorsmith, I'll wear a new suit in the field and get xp from taking hits. I just gave a noob a full suit of Marbari last night, and got xp from her as well, while we were hunting together.
I've also read that the user must be near you, for you to get the xp. Not sure about this, as a qualified for nov Merchant while alone and not crafting.