My understanding is that they do charge some fee to places like food trucks. The way it's structured, though, they encourage the users to keep some amount (c.

My understanding is that they do charge some fee to places like food trucks. The way it's structured, though, they encourage the users to keep some amount (c. $20) in their Venmo accounts, so that when you pay someone, it gets taken out of that first, then only falls back to your credit card or bank account when necessary. Depending on how frequently people cash out, they might even be able to make a small amount on interest by investing the amounts that people have on file, and just shifting the chits around.