I am on the Board of Directors of a regional vapers' social group, Smoky Mountain Vapers, in Knoxville, TN. We have quarterly
vape meets that consist of attendance raffles, paid advocacy raffles to support CASAA, games, AND as many local vendors as we can offer our attendees. There has never been aggression between vendors. There is obviously competition for market share, but in the years I have been associated with the group (since the very 1st meet-Spring 2011), the overwhelming message from vendors is that helping people find a safer alternative is their motivation. They all take great pride in helping people.
Ironically, I have been present when one vendor di not have specific merchandise that a customer wanted, and the vendor referred the person to a competitor, who they knew had what the customer was looking for.
There is actually a cooperative effort among B&Ms in Knoxville for the benefit of smokers' cessation.
Dunno about Vapebash/Vapecon, but that's been my experience at home.
