I've been to several Speed Dating events.
The first was terrible. But then I got serious about it, I read up a bit on the speed dating, started chatting up the host (always good to have an "IN" with the girl running the event), and asked others who were getting matches what they were doing.
Now when I walk in to an event, I OWN the place. I prefer these "speed dating" events to bars - everyone is there for the same reason. You know the girl you are talking to wants to pickup and is not there just to flirt.
If you want it to work, get serious about it. You have to walk in the door prepared.
Hope this helps