upon reading this I actually needed Google to figure out what Xfire was, I was hoping it would actually help me Play arcanum.
I've had a lot of games offer to install it for me, but I've refused everytime for fear of getting a virus or spyware and such...
I never install it either, but then again I never play games online, I'm more of a LAN-with-people-I-know-IRL when it comes to multiplayer.
There used to be a group of us did that back home, at least until we figured out how much cash could be made booking the free LAN room for ourselves and then making other people pay to join in. In our quest to maximise profits we had to sit out of the games ourselves.