Right now, peering agreements are the wild west. no. those days passed in the last century. you just don't know them. but then, you are not an operator so no surprise.
to be clearer. by count, the vast majority of peering is done by small ops informally. this represents a small fraction of the traffic. you don't see the peering agreements because there are no formal ones. and i guess it looks chaotic from the outside. it looks pretty normal from the inside. e.g., i have a research rack connected to the six, tell most folk there that i have neither eyeballs nor eye candy, but peer informally with folk such as r&e networks where i need to move data. oh, and the rack peers informally with my $dayjob, which might be the only informal peering which $dayjob does. makes sense from the inside, looks strange from the outside. you have to know my business model for it to make sense. the big kids peer very formally, which represents the majority of the traffic, and often does not happen at exchanges. like many bi-lateral business to business deals in the commercial world, the details are confidential. to you, it may look like the wild west. to the players, it's just business. randy