Bridal shows success?

Hello.  I am a wedding planner and have been in business for about 2 years now.  I am very active in networking, forums for helping couples, etc.  One area that I am not quite sure on is the value of bridal shows.  I realize depending on where you are they are handled differently (based on talking to vendors in other states), but overall would like opinions.

I've done a smaller one here for 2 years (Arizona).  Pretty good attendance especially for today's economy and a quality show.   I participate in all the 'give aways', handouts etc. of the show and for that receive bride contact list.  I am finding that honestly I cannot even get a no thank you from those attending...prizes for the overall show include free planning, free photography and the couple's never redeem them. I even have my own contest and sign up sheet and still nothing from the bride's.  I'm not alone on this.  I have been doing my vendor research and others have the same response.  I am not pushy nor do I spam so that is not the issue.  I offer a very competitive price so that is not the issue.

I am so tempted to do the bigger shows here in the Valley however if the smaller one renders absolutely nothing then what is going to be the outcome from a huge one where after 2 days the glazed looks on the attendees and the wall to wall traffic tells me that other than going home with freebies these people are at a loss due to the size of the show.  I've attended several and feel the same way and I'm not planning my own wedding!

So long story, but that is the dilema.  Do you participate in bridal shows? Do you find them successful for you?

Thanks!

Robbie