I guess so... I once walked into a hotel and aksed for a room. Then I asked if they had a corporate rate to which the lady responded "yes, but it's more expensive..."

I guess that some corporations just make contracts with chains and never check back whether the special rate they negotiated is higher or lower than the normal rates.

With conferences the organizers will usually ask the hotel to block a number of rooms for conference participants. This involves a risk of selling less rooms in the end than if they had just sold the rooms to the general public. I guess that's why the rate is often higher than the standard rate: availability guaranteed.

HTB.