This is dated as I was hired a decade ago, but I flat out go my call because of a job fair. Didn't have a single rec from anyone and just a boring average dude with 5000 and 2600 jet pic or so.
It certainly can't hurt.
And to address above regarding the in house job fairs rather than going to ones presented by OBAP, WIA, or whatever that air apps one is if it's still around... if the airline is offering an open house job fair I'd definitely attend that.