I actually think one Interaction decision they made (intentionally or unintentionally) that helped with engagement a lot is the lack of a queue system for becom

I actually think one Interaction decision they made (intentionally or unintentionally) that helped with engagement a lot is the lack of a queue system for becoming DJ. Forcing people to be first to click to become a DJ when one leaves means that anyone who wants to be DJ means that everyone who wants to DJ has to be paying close attention/very engaged in the room, which probably leads to more chats, more thought put into what they will spin, etc. This taps into people's natural desire to be seen and heard and impact the world around them, and also makes them more invested the longer they wait -- if you've been waiting for a DJ spot to open up for 30 minutes, or haven't been able to click in fast enough, you feel almost obligated to stay until you get one. And then once you get one, you feel like the cost of getting there was such that you don't want to give the seat up.