Ah, but you should discover that the faction that gave the artifact away
gained an NP. Thus are NP conserved. If you give a control artifact to
someone who doesn't have an NP to spend, then control of the npc remains
with the original faction.
Yes, an NP is more useful than the artifact is, so transferring the
objects isn't particularly useful unless you can find someone who doesn't
mind trading down.
We haven't found out yet whether you get the NP back if you drop the
artifact. I strongly suspect that it works as outlined above -- you keep
control of the NPC until someone with an NP to spend finds the object and
picks it up. But if you'd like to experiment and report back, feel free.
The Midnight Carnival