Not in my experience
My experience (from running a couple of conferences) is different that yours. No hotel ever gave us free space, no matter how many rooms we were likely to book. What we did get is a kickback on each room booked and comp rooms for our staff.
The real money maker, in my experience, is food and alcohol. The tabs on those were on the order of 10x the cost of rooms or conference space IRC (it's been a few years).
Biting the hand that feeds IT
