In my circle, FB invites are WAY overused, as my circle of friends/acquaintances are mostly all performers, who use FB invites to invite people to their shows, so I constantly have a flood of invites from people I haven't seen in ages. Real invites tend to get lost in the shuffle.
However, if it's the norm among your friends, go for it. But phone calls to follow up might not be a bad idea, in case any of them have FBs like mine.