If people couldn't pay to co-locate with the exchanges they would still compete for latency reductions. They would try to get in the building across the street.

If people couldn't pay to co-locate with the exchanges they would still compete for latency reductions. They would try to get in the building across the street. Or the one two blocks away. Or the one with a direct fiber connection. Being able to pay to co-locate with the exchange actually serves to democratize things because it puts everyone on a level playing field where they pay the exact same cost for the exact same access.