[ChuckMcM]

Well you have to understand that this was something the church was doing and Christians have a thing for numbers, 7 being one of them.

That being said, I always assumed that it was because it would create conversational tension, that it encouraged people to keep engaging in conversations. It seemed to work well in that regard in my experience.

I'll ping the organizer and see if there was any deep significance here or if it was just "I don't know, how about 7?" kind of thing.