Thank you, it was a real honor to win the ibtm Tech Watch award this year. I also am glad you like DB, our demo EventBot.
The top subjects are likely what you would expect, Directions, Parking, Wifi, but the variety of ways people ask for those and the other 100+ topics our EventBot handles is really the interesting thing. We support > 2.3 million ways to ask for the 100 plus topics. In fact I think there are about 33,000 ways people can ask for Wifi information alone.
We do not ask event participants specifically about the their satisfaction levels with the event's bot, we prefer to keep the focus on the overall event experience. What I can say is the number of 'Thank you' the bot receives is much greater than the complaints by about 50 to 1. Our average participant usage rate is ~57% with average user asks the event's bot > 4 questions. Of the complaints we do get most are about something else with the event like too noisy in a breakout session, food quality, and long lines at registration. The good news for the event planners is the complaints do not go on Twitter, we find by having another channel public complaints at the events we have been close to zero.