I know what Xfire is, but why should I use it?
Hmm, ok let's see... Ah, one way I use it for Raganrok is to determine when my friends are playing. This helps as my good mate and his brother play on a shared account. Now, I don't like his brother so I can check when his playing to avoid arkward confrontations.
Also, most of my close friends use this as opposed to msn, I guess that doesn't affect you =/
Not so much Ragnarok, but joining say, Counter Strike servers that my friends are playing is a matter of pressing "join game". Not to mention being able to view their frags and bag the shit outta them =P
Probebly the best and most defining feature is the ability to Instant Message in-game. It is so convenient =D No alt-tabbing lag crap. Especially when I'm playing a high resource game such as Battlefield 2, F.E.A.R, Crysis etc.
Um, what else... Er, logging of game hours if that's interesting? Records screenshots for you, and you can use voIP or whatever, like teamspeak I guess.
Etc etc...
Unless you prefer msn >.>
Did I mention the program takes little resources to run?
Ok so, there's limited uses for soul Ragnarok players, but for all round gamers... It's pretty damn handy.