When I photograph these events you have to ask yourself as a photographer is how is the client going to use the images, and what do they want their clients to get from this event. So in the case of this event the client was going to use the photos to promote the same event for 2014. The client wants prospective clients to see that they have industry leading speakers, the event is very interactive, there is a lot of networking among attendees, and that their is plenty of downtime time to informally chat with other attendees.
I also realize that clients want some abstract photos for their websites and marketing materials. The first photo below of a closeup of the microphone. This photo is now being used by Energy Dialagues, the company the produces the event, on their home page.