I have a ton of informal conversations with people I don't have formal meetings with, just because we happen to go to the coffee machine at the same time or happen to go eat lunch at the same time. Some of those conversations are non-job-related (which is valuable, since strong social connections with colleagues are valuable), but a lot end up being on job stuff. I end up just informally talking with sales people, customer service people, managers, etc, and hearing about stuff from their perspective or the stuff that's on their minds is incredibly useful.