I believe this idea is something for the marketing department to take up. With a large enough audience interested and a few big name companies willing to sponser...Overstock.com Coindesk, etc this would work.
I'm sure Coindesk would publish articles about the BitsharesXpo which would hit reddit spiking traffic to the BitshareXpo page, causing people to buy tickets. Doesn't necessarily have to be in USA, the first one could be in Hong Kong, I know we have lots of interested chinese investors. There is always someone that knows someone important that can get these things done.