I see no advantage in more exchanges. That only reduces the volume in each.
The idea is to reach more people and spread COOL around as much as possible. The greater the number of people that uses COOL, the more stable the coin becomes.
If we're just on one or two exchanges, sure volume would be higher but the number of people exposed to COOL would be a lot less.
A lot of people might not want to go through the trouble of creating a new account on an exchange just to buy COOL but if they get COOL on their favorite exchange then they might be tempted to invest a little
