How can day-only conference centers compete with hotels?

I just received this comment on this post about conference center business being on the rebound:

I recently started selling meeting space at a conference center. Up until now, most of my experience has been in conference planning. The location of my conference center is in the heart of a major city and must compete with large hotel chains in and around the area. We are among a small number of properties that meet IACC standards in the area. Your comments are entirely true, but how are conference centers that can not accomodate over night guests, able to keep up with hotels? Any suggestions? sales tips or contacts in this specific industry?

If you have any suggestions for her, please drop me an e-mail, and I'll pass it along to her. We hear that day meetings are on the rise, but how to find the planners for those meetings? I don't know. Any help you can provide would be much appreciated.