Coffee is effectively a metaphor for a highly public, time-limited meeting that either party can escape at any moment. It can be conveniently extended ("I'm co

Coffee is effectively a metaphor for a highly public, time-limited meeting that either party can escape at any moment. It can be conveniently extended ("I'm could really go for a burger, you?") or aborted ("I'm sorry, I agreed to meet my friend in ten minutes, it was nice meeting you"). It's low cost, with no obligation to stick around to get your money's worth. It's not literal. Paddling on a lake is not a safe, easily aborted situation. Group events are where it's at. This is socially similar to meeting by networking through friends, even if you have few close friends, or boring ones.