Hi, if you are a trader with large amounts of parcels then yes go direct to the couriers and screw them down, play them off against each other, maybe act in a way you wouldn't normally dream of.
If you are like me sending out on average 20 parcels a week then get in touch with Atom Logistics, they are company that you trade with (customer service is superb) and they trade direct with the courier so you get the prices a larger company might get even though you ship less than the amount the courier would want you to to get a direct account at a good price. (mention my name, Gary from Cross Camping, you never know I might get a better price when I try to screw them down again lol)