BOOM is widely used in the beer pong community for pretty much any reason. It is shouted as loud as possible so that everyone is aware of what just happened and are now compelled to BOOM as well. Can be used in conjuction with LFG
Mike - "I just smashed some bids tonight"
Chris - "BOOM!!"
Mike - "LFG"
Crowd - *chanting Iron Wizard*
Pong Ferrigno - *hits cup*
All in attendance - "BOOOOOOOOOOOOOOM!!!!"