Sort:  

do you have some examples? Centralized exchanges charge fees too and in some cases like coinbase the fees are crazy expensive unless you use their GDAX system. If you use GDAX the fees are free or so they say. I still think that the exchanges use the spread to their advantage and you may think you are getting 0 fees but I have a feeling they are still making money off of us all.

GDAX is free if you use Limit Orders. Market orders and any taker order charge a fee.