Which Pays better: Bartending or Doing Liquor Promotions?

I've been working in promotional marketing as a brand ambassador/promotional model for quite a while now and I've been booked for both non-professional bartending work and low end liquor promos. Anybody who does it knows that event and promotional work is very sporadic and now that I'm ready to go to college, I'd like to find a steady liquor serving gig to put myself though school. So which pays better, professional bartending or doing high end liquor promotions? Also I'd really like to bartend at a casino. So which place averages more tips for bartenders between night clubs and casinos?