You'll get event planner nights and points if you book ten or more rooms through the sales department rather than booking through the website. That's about it. If individual employees are paying their own bills and getting reimbursed (and earning MR points) you can still get the event planner points by creating the block and having them book into it. Of course you need to have a very close idea of how many rooms you will need in order to avoid being bit in the butt by the contract if the block does not fill. And if you need fewer than ten rooms at a location, you're SOL.